Data transfer apparatus and data transfer system
FIELD OF THE INVENTION 
     The present invention relates to an apparatus and system for the transfer of digital data. 
     BACKGROUND OF THE INVENTION 
     A typical prior art system is shown in FIG. 1. In this prior art system, stereo sound signals of right and left channels are converted into signals of four channels for surround processing, and are digitally processed. Analog sound signals of right and left channels are fed from an input terminal 1 into an analog/digital converter 2, and are converted into digital signals of right and left channels, and are applied to a digital signal processor 4 from a line 3. The digital signal processor 4 arithmetically processes these digital sound signals of two channels, outputs than to a line 5, and feeds them to another digital signal processor 6. In this digital signal processor 6, sound signals of four channels are digitally processed, and the sound signals of four channels are output to a line 7. These signals of four channels are, in order to enhance the presence or other effect, delivered individually to speakers disposed at the front left side FL, front right side FR, rear left side RL, and rear right side RR of the listener to drive them. 
     In a register 8 provided in the digital signal processor 6, the sound signals of four channels digitized in the form shown in FIG. 2 are stored. The sound signals delivered to these speakers are identified by the same reference codes FL, FR; RL, RR. These signals FL, FR; RL, RR of four channels are composed of 16 bits each. The sound signals of four channels delivered from the line 7 are supplied to two digital/analog converters 10 and 1l from a changeover circuit 9. In one digital/analog converter 10, the sound signals of front left and right side, FL and FR, are individually output, and in the other digital/analog converter 11, the sound signals of rear left and right side, RL and RR, are output. 
     Between the input data to the digital signal processor 6 through line 5, and the output data from the digital signal processor 6 output to line 7, the number of bits doubled, and the clock signal fed to the digital signal processor 6 must have double the frequency of the clock signal to be supplied to the digital signal processor 4 and analog/digital converter 2, and hence two clock generators are needed. 
     Meanwhile, the changeover circuit 9 must change over the sound signals so as to supply the digital sound signals of front left and right side, FL and FR, in the register 8 to one digital/analog converter 10, and digital sound signals of rear left and right side, RL and RR, to the other digital/analog converter 11. Accordingly, the changeover circuit 9 requires (a) a counter for counting the clock signals in tune with clock signals for outputting each bit of data from the register 8, and (b) a flip-flop which is kept in one stable state until the counting by this counter reaches a total of 32 bits which is the number of bits (=16 +16) of the digital sound signals of the front left and right side, FL and FR, and is kept in another stable state until the counter has counted the remaining 32 bits which is the number of bits (=16+16) of the digital sound signals of the rear left and right side, RL and RR. In addition, on the basis of the output of this flip-flop, it is necessary to change over the digital/analog converters 10 and 11 to activate them. Therefore, the changeover circuit 9 comes to have a relatively complicated structure. Still more, since the construction is completely different between the four-channel system and two-channel system, a problem exists in the compatibility. 
     To solve these problems, for example, a monostable multivibrator 12 is disposed in a digital signal processor DSP12, and a clock signal is generated upon rise and fall of the clock signal from the clock signal generator 5; in other words, a clock frequency having double the frequency of the clock signal from the clock signal generator 5 is created to transfer data. 
     However in such a configuration, to always generate a doubled frequency clock signal, when debugging or when transferring a large quantity of data for other applications, that is, when it is necessary to change the clock signal from the clock signal generator 5 to a higher frequency, the monostable multivibrator 12 cannot generate a doubled frequency clock of the changed high speed clock frequency by accurately following up because of the fluctuations of capacitors and circuit constant elements contained in the monostable multivibrator 12, so that it was impossible to transfer data at a high speed. 
     It is hence a primary object of the invention to provide a data transfer apparatus and a system capable of transferring data in a simple structure by using a common external clock signal for data transfer between systems to dispose parallel transfer registers for transferring data, and to transfer data in time sharing manner. 
     It is other object of the invention to provide a data transfer apparatus and a system capable of changing over the serial digital signal from the digital signal processor in the front stage to the two digital signal processors in the rear stage, and applying these signals, in a simple structure. 
     It is a different object of this invention to provide a data transfer system capable of transferring data in a simple structure by reducing the number of registers, by also using part of the transfer register for data transfer as buffer register. 
     It is a further different object of this invention to provide a data transfer apparatus capable of coping with changes in the frequency of the external clock signal when increasing the speed of data transfer and when debugging, by changing the external clock signal into a frequency of a desired multiplicity and selectively outputting it. 
     SUMMARY OF THE INVENTION 
     The present invention may be effected by providing a data transfer system comprising n transmitting registers and m receiving registers, wherein n and m are greater than one, the system sequentially switchingly designating the transmitting registers and the receiving registers to effect data transfer, so that contents of the transmitting registers are transferred correspondingly to the receiving registers wherein: 
     the contents of the respective transmitting registers are separated into a plurality of groups and transferred by the group; 
     the respective receiving registers sequentially store the contents of the group from the respective transmitting registers designated correspondingly thereto; 
     the data transfer of the contents of the respective groups from the respective transmitting registers effected at least a number of times equal to the greater of n and m is treated as one cycle, and repeatedly effected for plural cycles, whereby all the data stored in the respective transmitting registers are transferred to the corresponding receiving registers thereof; and 
     the transmitting registers of data transfer after each cycle and the receiving registers are sequentially matched with each other, by correspondence made between the transmitting register and receiving register in the first data transfer for each cycle. 
     The invention may also be effected by providing a data transfer system in which a transmitting register for externally transmitting transfer data is used also as a buffer register for writing the transfer data so as to temporarily store the data therein, the system comprising: 
     a plurality of shift register groups for externally transmitting the transfer data or writing the transfer data internally sent thereto; and 
     switching means for alternately selecting the shift register groups so as to effect the data transfer; 
     wherein the respective shift register groups alternately transmit the transfer data externally and write the transfer data sent internally thereto in accordance with the selection made by the switching means; 
     or by providing a data transfer apparatus comprising: 
     a first digital signal processor having two registers for storing data to be transmitted and for outputting the data serially in response to an external clock signal, and a changeover means for alternately and sequentially outputting the outputs from the two registers to a single output line in response to the clock signal; 
     two second digital signal processors for selectively receiving data from the output line in response to a change in the clock signal; and 
     wherein the clock signal is applied to one of the second digital signal processors, and an inverted clock signal is applied to the other of the second digital signal processors; 
     and wherein the first digital signal processor has a frequency converter means for converting the external clock signal into a clock signal having a frequency of a specified multiplicity and a clock selector means for selectively outputting the clock signal from the frequency converter means and the external clock signal; 
     or by providing a data transfer system for writing each group data of transfer data into shift registers for data transfer almost simultaneously in which a transmitting register for externally transmitting transfer data is used also as a buffer register for writing the transfer data so as to temporarily store the data therein, the system comprising: 
     m+1 shift registers for storing one word data obtained by dividing the group data into m sub-groups wherein m is 2 or a larger integer; 
     a first switching means for sequentially selecting the shift registers, and externally transmitting the group data by one word data each; and 
     a second switching means for selecting other m shift registers not selected by the first switching means and for writing the group data therein; wherein 
     when the shift register in which the final one word data of the specified group data is selected by the first switching means, the next group data is written into the remaining m shift registers by the second switching means. 
     The invention may also be effected by providing a data transfer system for reading out group data of transfer data almost simultaneously from shift registers for receiving the data, in which a receiving register for receiving the transfer data is used as a buffer register for temporarily storing the received transfer data from outside to read out according to needs, the system comprising; 
     m+1 shift registers for storing one word data obtained by dividing the group data into m sub-groups wherein m is 2 or a larger integer; 
     a first switching means for sequentially selecting the shift registers and receiving the group data from outside by one word data each; and 
     a second switching means for selecting other m shift registers not selected by the first switching means and for writing the group data; 
     wherein the specified group data is received by specified m shift registers by the first switching means, and when a next shift register is selected, the group data is read out from the specified m shift registers by the second switching means; 
     or by providing a data transfer system in which a receiving register for receiving transfer data from outside is used also as a buffer register for storing the transfer data received from outside to be read out according to needs, the system comprising: 
     a plurality of shift register groups for receiving the transfer data from outside or reading out the received transfer data internally; and 
     a switching means for alternately selecting the respective shift register groups so as to receive the transfer data; 
     wherein the respective shift register groups alternately receive the transfer data from outside and internally read out the received transfer data in accordance with the selection made by the switching means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram showing a sound signal processing apparatus in the prior art; 
     FIG. 2 is a diagram showing the format of the data stored in a register 8 in the prior art shown in FIG. 1; 
     FIG. 3 is a system diagram of a configuration according to an embodiment of the present invention; 
     FIG. 4 is a block diagram showing an example of a basic configuration of FIG. 3; 
     FIG. 5 is a block diagram of an embodiment of the invention; 
     FIGS. 6(1)-6(5) are waveform diagrams for explaining the operation of the embodiment shown in FIG. 5; 
     FIG. 7 is a flowchart to explain the operation of the embodiments shown in FIG. 5 and FIGS. 6(1)6(5); 
     FIG. 8 is a block diagram of another embodiment of the present invention; 
     FIG. 9 is a block diagram of a different embodiment of the present invention; 
     FIG. 10 is a block diagram showing a configuration of an embodiment of this invention; 
     FIGS. 11(1)-11(5) are timing charts to explain the writing action of the same configuration; 
     FIGS. 12(1)-12(6) are timing charts to explain the reading action of the same configuration; 
     FIG. 13 is a block diagram showing a configuration of an embodiment of the present invention. 
     FIG. 14 is a block diagram showing an example of structure of a decoder 35; 
     FIG. 15 is a block diagram showing an example of structure of a decoder 36; 
     FIGS. 16(1)-16(5) are timing charts to explain the operation of the same embodiment; 
     FIGS. 17(1)-17(2) are diagrams to show the relationship between the data transfer sequence and register; 
     FIG. 18 is a block diagram of an embodiment of the present invention; 
     FIGS. 19(1)-19(3) are diagrams to show the composition of combined information A to C to be output to a line 16 when data is written into a memory M1 of a second processor U2 from a first processor U1; 
     FIGS. 20(1)-20(2) are diagrams to show the composition of combined information D and E to be output to the line 16 when reading out the data from the memory M1 of the second processor U2 into the first processor U1; 
     FIGS. 21(1)-21(5) are waveform diagrams to explain the operation of the embodiment shown in FIG. 18; 
     FIG. 22 is a flowchart to explain the operation of the embodiment shown in FIG. 18; 
     FIG. 23 is a block diagram of a main embodiment of the present invention; 
     FIGS. 24(1)-24(6) are diagrams to explain the operation when the first plurality n and the second plurality m are equal to each other in the embodiment shown in FIG. 23; 
     FIGS. 25(1)-25(8) are waveform diagrams to explain the operation when the first plurality n is less than the second plurality m; 
     FIG. 26(1)-26(8) are waveform diagrams to explain the operation when the first plurality n exceeds the second plurality m; 
     FIG. 27 is a block diagram of a different embodiment of the present invention; 
     FIG. 28 is a block diagram showing the composition of the receiving side of an embodiment of the invention; 
     FIG. 29 is a block diagram showing he composition of the transmitting side of the same embodiment; 
     FIG. 30(1)-30(6) are timing charts to explain the operation of the same embodiment; 
     FIG. 31 is a block diagram of a sound signal processor 13 in an embodiment of the present invention; 
     FIGS. 32(1)-32(9) and FIGS. 33(1)-33(2) are waveform diagrams to explain the operation of the abovenoted embodiment; 
     FIG. 34 and FIG. 35 are block diagrams showing a basic composition of the transmitting side and receiving side according to an embodiment of the present invention; 
     FIGS. 36(1)-36(7) are timing charts to explain the data transfer by the configuration shown in FIG. 34 and FIG. 35; 
     FIG. 37 is a block diagram of an embodiment of the present invention; 
     FIGS. 38(1)-38(8) are waveform diagrams to explain the operation of the embodiment shown in FIG. 37; 
     FIG. 39 is a block diagram showing a configuration of a sound signal processor 41 in an embodiment of the present invention; 
     FIGS. 40(1)-40(5) are waveform diagrams to explain the operation of the embodiment shown in FIG. 39; 
     FIG. 41 is a drawing to explain the storing the transferring actions of data in processors 44 and 48; 
     FIG. 42 is a block diagram showing the composition of processors DSP3 and DSP4 for transferring data in an embodiment of the invention; 
     FIGS. 43(1)-43(4) are waveform diagrams to explain the data transfer action between processors DSP3 and DSP4; 
     FIG. 44 is a block diagram to show the configuration when the data transfer system of the invention is employed in the transfer of an acoustic signal; 
     FIG. 45 is a block diagram of an embodiment of the present invention; 
     FIG. 46 is a block diagram showing the details of part of the constitution of the embodiment shown in FIG. 45; 
     FIGS. 47(1)-47(4) are waveform diagrams to explain the operation of data transfer in the constitution shown in FIG. 46; 
     FIG. 48 is a block diagram of a different embodiment of the present invention; 
     FIG. 49 is a block diagram showing the configuration near processor DSP4 in an embodiment of the present invention; 
     FIG. 50 is a drawing to explain the operation when the function of an electronic variable resistor is added to the processor DSP4; 
     FIG. 51 is a block diagram to show another embodiment of the invention; 
     FIG. 52 is a block diagram of an acoustic processor of the invention. 
     FIGS. 53(1)-53(7) are waveform diagrams to explain the operation of FIG. 52; 
     FIG. 54 is a block diagram of a processor; 
     FIG. 55 is a block diagram of an acoustic signal processor of the present invention; 
     FIGS. 56(1)-56(5) are waveform diagrams to explain the operation of FIG. 55; 
     FIG. 57 is a block diagram of a processor; and 
     FIG. 58 is a block diagram showing a configuration of a sound signal processor 21 in an embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 3 is a system diagram of a configuration according to an embodiment of the present invention, and FIG. 4 is a block diagram showing an example of the basic configuration of FIG. 3. Referring to these drawings together, the configuration of this embodiment is described below. This configuration controls, for example, a car-mounted acoustical apparatus possessing several functions such as a radio receiver of the FM waveband and the AM waveband, a cassette tape recorder, a compact disc player, and a digital audio magnetic tape player (DAT). 
     This embodiment possesses signals of the AM waveband receiver AM, the FM waveband receiver FM, the cassette tape recorder CS, the compact disc player CD, and the digital audio magnetic tape player DAT. The outputs of receivers AM, FM, and cassette tape recorder CS are selected by a changeover switch SS1. This selected output is passed through a lowpass filter LPF, in which high frequency noise is removed, and is fed to an analog-to-digital converter (A/D converter) ADC to be digitized, and its output is fed to digital signal processors (hereinafter called processors) DSP1 and DSP2. 
     The outputs of processors DSP1 and DSP2 are fed to a digital-to-analog converter (D/A converter) DAC to be converted into analog signals, which are passed through another lowpass filter LPF to remove high frequency noise, and are delivered from speakers SP as sound through an amplifier AMP. On the other hand, outputs from the compact disc player CD and digital audio tape player DAT are selected by changeover switches SS2 and SS3, and the selected output is fed into processors DSP1 and DSP2. The processors DSP1 and DSP2 are controlled by a microcomputer CM, to which are connected external memories EM1 and EM2 such as static memories (S-RAM). 
     FIG. 4 shows the connection state of the microcomputer CM and processor DSP1. The processor DSP1 comprises a receiver RC and a sender SD. The receiver RC and sender SD possess mantissa registers RR1, RR2, RR3, and RR4; and SR1, SR2, SR3, and SR4 for storing the mantissa sections of the floating decimal point type data to be received or sent, and also have index registers RI1, RI2, RI3, and RI4; and SI1, SI2, SI3, and SI4 for storing the index sections. In these registers (collectively mentioned by reference codes RR, SR; RI, SI), buffer registers Ra1 to Ra8; Rb1 to Rb8 (collectively mentioned by reference codes Ra, Rb) are disposed correspondingly. 
     The buffer registers Ra and Rb are connected to a data bus DB, to which are connected central processing unit CPU and memory M, by way of plural gates G1 and G2, respectively. 
     The processor DSP1 is equipped with a receiving register RX and receiving-transmitting register RT to be used in data transfer with the microcomputer, and the received data is stored in either register RX or RT by means of a changeover switch SS4. There is a cycle still controller CC for controlling the operations of the registers RX and RT. The microcomputer CM is furnished with a transmitting register TX and a receiving register RX for transmitting and receiving data between the above registers RX and RT, and there are buffer registers BT and BR for exchanging data between these registers RX and TX. 
     FIG. 5 is a block diagram of an embodiment of the present invention. By the command from a first processor A, (a) the data stored in the storage region of a memory M1 provided in a second processor B is read out and received in the first processor A, or (b) the data from the first processor A may be written into the storage region of the memory M1. From the transmitting register TX1 of the first processor A, a signal composed of a total of 24 bits in units of 8 bits each is sent out in the sequence of bits to the receiving register RX2 of the second processor B by way of a line 16. From the transmitting register TX2 of the second processor B, a bit is sent out in the sequence of bits to the receiving register RX1 of the first processor A through a line 17. 
     From the first processor A to the second processor B, a 24-bit signal is sent out through the line 16 as stated above, and the first two bits of these 24 bits are a command to instruct reading or writing, and this command is fed to a decoder 19 for decoding this command by way of a line 18. In the remaining 22 bits of the receiving register RX2, the address information for reading and writing, or data for writing is stored. The address information is supplied to an address decoder 20, so that the address in the storage region in the memory MI is specified. The 22-bit data of the receiving register RX2 is fed to the memory M1 from the line 21, so that the data through the line 21 is written in the store region specified by the address decoder 20. When reading out the data from the memory M1 and transferring it to the first processor A, the data stored in the store region of the memory M1 in which the address is specified by the signal from the address decoder 20 is fed to the transmitting register TX2, and the content of this transmitting region TX2 is transferred to the receiving register RX1 of the first processor A by way of the line 17. The registers TX1, RX1 in the first processor A are controlled by a control circuit 22. In the second processor B, a control circuit 23 is installed. This control circuit 23 controls the address decoder 20 and memory M1 in response to the signal from the command decoder 19, and also sends out a control signal TE to the control circuit 22 by way of the line 24, and receives a control signal CS from the control circuit 22 through the line 25. 
     FIGS. 6(1)-6(5) are waveform diagrams to explain the operation of the embodiment shown in FIG. 5, and FIG. 7 is a flowchart to explain its operation. This flowchart is realized by hardware. When the control signal CS is a logic 1, it is designed to return to the initial state (reset) by resetting the transfer block at step n20. Changing from step n1 to step n2, a determination is made as to whether or not the control signal CS is a logic 0, and this control signal CS is indicated in FIG. 6(1), and when it is judged to be low level, it means that it is necessary to transfer the signal from the first processor A to the second processor B, thereby advancing to step n3. Here, the control signal TE, which is a logic 0, is supplied from the control circuit 23 to 22. The control signal TE is intended to permit transfer of signals, which is indicated in FIG. 6 (2). 
     At step n4, a determination is made as to whether or not the transfer action to receiving register RX2 of the second processor B is finished, that is, whether or not the flag RXF is a logic 1, and when the receiving register RX2 is empty, the operation advance to step n5. Here, from the transmitting transistor TX1 of the first processor A to the receiving register RX2 of the second processor B, the signal of one bit out of 24 bits is transmitted through the line 16, in synchronism with the clock signal indicated in FIG. 6 (5). At step n6, the control signal TE becomes a logic 1, and the operation returns to step n4. Thus, as shown in FIG. 6 (3), signals S1, S2, and S3 of 8 bits each are sequentially stored in the receiving register RX2. Of the first 8-bit signal S1, the first two bits are a command to express reading or writing as stated above, and the remaining 6 bits of the signal S1 and the other two signals S2 and S3 are address information of 22 bits in total for specifying the address in the store region in the memory Ml. 
     After the signal is stored in the receiving register RX2, internal arithmetic processing is done in the second processor B. 
     At step n4, when the completion of the transfer of the 24-bit signal to the receiving register RX2 is judged, the operation goes to next step n7. The command decoder 19 decodes the first two bits of the command, and feeds it to the control circuit 23. As a result, at step n8, a determination is made as to whether the command is a reading command or a writing command. If a reading command, the operation goes to step n9. At this step, the address information stored in the receiving register RX2 is decoded by the address decoder 20, and the content in the storage region of the memory Ml in which the address is specified by this is stored in the transmitting register TX2. At step n10, as shown in FIG. 6 (2), the control signal TE is a logic 0, and at the next step n11, a determination is made as to whether or not the signal to be transmitted is present in the transmitting register TX2, that is, whether or not the flag TXF is a logic 1. Any signal to be transmitted is present in the transmitting register TX2, and at step n12, the data is transferred sequentially bit by bit to the receiving register RX1 of the first processor A through line 17 in synchronism with the clock signal shown in FIG. 6 (5). At step n13, the control signal TE becomes a logic 1. After all the data in the transmitting register TX2 is sent out, the operation advance from step n11 to step n14, and the flag RXF becomes a logic 0. 
     The state of the transfer of data from the transmitting register TX2 to the receiving register RX1 through line 17 is as shown in FIG. 6 (4), and signals S11, S12, and S13 in the unit of 8 bits each are sequentially output. 
     When writing data from the first processor A into the memory M1 of the second processor B, the operation moves from step n8 to step n15. The address information contained in signals S1, S2, and S3 is decoded in the address decoder 21. At step n16, a determination is made as to whether or not a signal is present in the receiving register RX2, and if there is no signal left over in the receiving register RX2, the operation advances to step n17, and the signals S11, S12, and S13 to express the data to be written are sequentially transferred bit by bit to the receiving register RX2, and stored, as shown in FIG. 6 (4). At step n18, the control signal TE becomes 0 logic 1. When signals S11, S12, nd S13 are stored in the receiving register RX2, the operation moves from step n16 to step n19, and the data of the receiving register RX2 is written into the memory region in which the address is specified through the line 21 by means of the address decoder 20 in the memory M1. 
     In this way, in the above embodiment, the second processor B is composed of hardware comprising the receiving register RX2, command decoder 19, address decoder 20, memory M1 and transmitting register TX2, and the reading and writing action by these units are carried out by the hardware, and arithmetic processing other than data transfer can be effected by the control circuit 23 in the processor B, while the data can be transferred at high speed. 
     FIG. 8 is a block diagram of the second processor B1 of a different embodiment of the present invention. In this embodiment, which is similar to the foregoing one, corresponding parts are identified with same reference numbers. What is of note here is that the data stored in the memory M2 of the second processor B1 is only read out in the first processor A. Therefore, to the receiving register RX2, only the address information for specifying the address in a desired memory region of the memory M2 is transferred by way of the line 16. The address decoder 20 decodes this address information, and consequently the data which is the content stored in the store region of the memory M2 is applied to the transmitting register TX2. This data is transferred from the transmitting register TX2 into the first processor A by way of the line 17. When reading only in this way, the configuration is simplified as compared with the foregoing embodiment. 
     FIG. 9 is a block diagram of a further different embodiment of the present invention. In this embodiment, which is similar to the foregoing ones, corresponding parts are identified with same reference numbers. Here, the data from the first processor A is only written into a desired storage region in the memory M3 of the second processor B2. First, from the first processor A, the address information is transferred to the receiving register RX2 of the second processor B through line 16. This address information is decoded by the address decoder 20. Next, from the first processor A, the data to be written in the receiving register RX2 is transferred through line 16. This data is fed from the receiving register RX2 into the memory M3, and the data is thus written into the store region in which the address is specified, by the address decoder 20. In such an embodiment for writing only, the configuration may be simplified as compared with the embodiment shown in FIGS. 5 to 7. 
     This invention may be also executed in relation to the processing of sound signals, and may be also embodied in other technical fields. 
     According to the present invention, as understood from the description herein, the data can be transferred at a high speed, and in the first and second processors adverse effects on other arithmetic processing by data transfer may be avoided. 
     FIG. 10 is a block diagram showing a configuration of an embodiment of the present invention. This embodiment contains an arithmetic control device 21 realized by, for example, an arithmetic processor, and a processor 22. The arithmetic control device 21 comprises a buffer register for transmission 23 and a buffer register for reception 24, and these buffer registers 23 and 24 are connected to the address bus and data bus contained in the arithmetic control device 21 to access the data. Transmitting register 25 and receiving register 26 are connected to these buffer registers 23 and 24. 
     The processor 22 comprises, for example, a 4-bit command register 27 and a 12-bit address register 28, and to these registers 27 and 28, transmission data D1 is fed from the transmitting register 25 of the arithmetic control device 21. The content of the command register 27 is analyzed in the command decoder 29, and a corresponding action is executed in the processor 22. On the other hand, the registers 27 and 28 are read by a cycle still control unit 30, and the address data is exchanged with the address bus 31 between timings of arithmetic processings. 
     The processor 22 also possesses a data register 32 of, for example, 24 bits for storing the data main body to be transmitted which is contained in the transmission data D1. It is an important object of this embodiment that this data register 32 can be used commonly for transmission and reception for the arithmetic control device 21. In these registers 27, 28 and data register 32, the clock signal CK generated by the arithmetic control device 21 is entered as being changed over by the changeover switch 33 as described below. 
     The latch control signal LC as stated later to be delivered from the arithmetic control device 21 is entered in the data latch control unit 34 which is provided in the processor 22, and the data latch control unit 34 correspondingly controls the changeover mode of the changeover switch 33 and the data latch actions in the registers 27, 28, and 32. The content in the data register 32 is written into the memory 36 realized by, for example, a random access memory, by the address data supplied in the address bus 31 through the data bus 35, and this content is read out. 
     FIGS. 11(1)-11(5) are timing charts to explain the writing action in the configuration shown in FIG. 10. Referring to also FIG. 2, the writing action of the embodiment is explained below. At time t1, in FIG. 11 the arithmetic control device 21 changes the chip select signal CS to a low level as shown in FIG. 11 (1), and the processor 22 is selected. In turn, the processor 22 changes the transfer control signal TE to a low level, and the data transfer between the arithmetic control device 21 and processor 22 is realized. At this time, the data latch control unit 34 is also reset, and the changeover switch 33 is changed over to the side of registers 27, 28. 
     Afterwards, as shown in FIG. 11 (4), as the transmission data, the command data meaning the writing command and the address data indicating the destination of writing of the data main body are transferred to the command register 27 and the address register 28, according to the clock signal CK entered from the arithmetic control device 21. When transfer is started, the latch control signal LC is set to a low level as shown in FIG. 11 (3). Furthermore, at time t2 when this transfer is over, as shown in FIG. 11 (3), the latch control signal LC is set to a high level. At this timing, the command data and address data are latched in the command register 27 and address register 28. At the same time, the changeover switch 33 is changed to the side of the data register 32 by the data latch control unit. Next, in succession, as shown in FIG. 11 (2), the transfer control signal TE becomes a high level, and the transfer is prohibited. 
     At time t3, the transfer control signal TE becomes a low level so as to be ready to transfer again, and the data main body to be stored in the address which is stored in the address register 28 is transferred to the processor 22 as shown in FIG. 11 (4). The arithmetic control device 21 delivers a clock signal CK, and transfers the data main body main body to the data register 32. At the same time, the latch control signal LC is set to a low level. When this latch action is over, the latch control signal LC is set to a high level, and the changeover switch 33 is changed again to the side of registers 27 and 28. 
     Consequently the transfer control signal TE becomes a high level to prohibit transfer. Later, the chip select signal CS becomes a high level, and the writing action is over. 
     FIGS. 12(1)-12(6) are timing charts to explain the data reading processing from the processor 22 by the arithmetic control device 2 in the configuration shown in FIG. 10. Referring to FIG. 3, the data reading processing is explained below. In the reading process, in this configuration, first the chip select signal CS is set to a low level at time t5 as shown in FIG. 12 (1), and the processor 22 is selected. Then the transfer control signal TE becomes a low level, and the data can be transferred between the arithmetic control device 21 and the processor 22. From the arithmetic control device 21, as shown in FIG. 12 (4), the command data to show the reading command, and the address data to specify the address in, for example, the memory 36 of the processor 22 in which the data to be read is stored are transferred to the processor 22. At the same time, the latch control signal LC is set to a low level. 
     At this time, similarly to the case of FIG. 11, the latch control signal is reset by the rise of the chip select signal CS, and the changeover switch 33 is changed to the side of registers 27 and 28. Thus, the command data and address data which are transmission data D1 are written into the command register 27 and address register 28. The contents of these registers 27 and 28 ar latched in the command register 27 and address register 28 at the timing where the latch control signal LC becomes a high level at time t6 in FIG. 12. At this time, the changeover switch 33 is changed to the side of register 32. 
     The latched address information is decoded next in the cycle still control unit 30, and the data of the corresponding address in, for example, the memory 36 provided in the processor 22 is read out, and is stored in the data register 32. At time t7 after such storing, the transfer control signal TE becomes a low level. Afterwards, as shown in FIG. 12 (5), the data stored in the data register 32 is read out according to the clock signal CK from the arithmetic control device 21, and is stored as the reception data D2 of the arithmetic control device 21. 
     When data transmission is over in this way, same as in the case of FIG. 11, the latch control signal LC becomes a high level, and the transfer control signal TE and chip select signal CS sequentially become a high level, thereby finishing the reading processing. 
     In the above writing processing and reading processing, when the data to be written after time t3 in FIG. 11 has, for example 24 bits, the time required for this writing action is 753 μs, nearly same as in the prior art, as calculated by the present inventor. 
     On the other hand, when reading data out of the processor 22, as explained by reference to FIG. 3, the address of the data to be read out is transferred, and in this case, too, the necessary time has been confirmed to be nearly 753 μs, same as in the prior art. 
     As stated above, the configuration shown in FIG. 10 can realize a same action as in the prior art. In this embodiment, the data register 32 is used for both reception and transmission, and the transfer relationship has been confirmed to be reduced by about 30% as compared with the prior art shown in FIG. 2. Incidentally the data length to be transferred may be, for example, 40 its (5 bytes) in both reading and writing processings, the transfer time can be shortened by about 36% as compared with the prior art in the data reading action. 
     In this embodiment, meanwhile, the input destination of the data delivered from the control device is changed over by changing the clock applied to the first and second memory means, but otherwise the data transfer route itself to the first and second memory means may be changed over. 
     In this case, however, it is necessary to design so as to taken in the data immediately when a specified number of pieces of data is entered, and as a result the hardware configuration becomes complicated and the time to take in the data is defined, which are actually demerits. 
     In this embodiment, moreover, a synchronous communication to synchronize with the external clock is shown, but this invention is also applicable to a synchronous communication (start/stop synchronous communication) by using clock and others generated inside. 
     Thus, according to the invention, it is possible to transfer data at high frequency by a simple construction. 
     FIG. 13 is a block diagram showing a configuration of an embodiment of the present invention. This embodiment comprises an arithmetic control device 21 realized, for example, by arithmetic processing unit, and a processor 22. 
     The arithmetic control device 21 is composed of a transmitting register 23 and a receiving register 24, and the transmitting register 23 delivers the write data DW into the processor 22, while the processor 22 sends the read data DR into the receiving register 24. 
     The processor 22 incorporates the transfer register 27 composed of the address register 25 and data register 26 for storing the address and data to make up the write data DW, and other data register 50 for delivering internal data. The content of the transfer register 27 is stored in the address register 29 and data register 30 which make up the buffer register 28. The contents of the address register 29 and data register 30 are exchanged with the address bus 31 and data bus 32 of the processor 22. 
     The processor 22 is provided with a gate control unit 33 for various logic gates (not shown). There is also a binary counter 34 for counting the clock signals CK supplied from the arithmetic control device 21. The output of the binary counter 34 is supplied in parallel to the decoders 35 and 36. The outputs of the decoder 35 and 36 are fed into one of the input terminals of two-input AND circuits 37 and 38, respectively. 
     To the AND circuit 38, a control signal R/W for indicating either the reading action state or writing action state to the processor 22 is entered, depending on whether the level is high or low, from the arithmetic control device 21 through the line 39 as state later. At the other input terminal of the AND circuit 37, a signal being inverted from the control signal R/W in the inverter circuit 40 is fed. The outputs of the AND circuits 37 and 38 are entered in the OR circuit 41, and the output of the OR circuit 41 is supplied to the address register 29 and data register 30 as a latch control signal. 
     FIG. 14 and FIG. 15 are block diagrams showing the configuration of the decoders 35 and 36. I this embodiment, of the data transferred between the arithmetic control device 21 and the processor 22, the address data has 16 bits and the main body data has 24 bits, and therefore, the data length of 40 bits is assumed in the following explanation. The decoder 35 uses the output of the lower 6 bits (b5,64,b3,b2,b1, and b0) of the binary counter 34, for example as shown in FIG. 14. This output of lower 6 bits is entered in the AND circuit 43 through signal lines 42 to 47 from the lower bit side. On the signal lines 42, 43, 44, and 46, there are respective inverter circuits 49 to 52. The output of the AND circuit 48 becomes high level when the lower 6 bits of the binary counter 34 are 
     
         (b5,b4,b3,b2,b1,b0)=(1,0,1,0,0,0)                          (1) 
    
     and this case corresponds to 40 in decimal notation. 
     The decoder 36 basically has the same constitution, and the lower 5 bits of the binary counter 34 are used. From the lower bit side, the content of each bit is entered in the AND circuit 58 through signal lines 53 to 57. At this time, inverter circuit 59 to 62 are disposed on the signal lines 53 to 56. By the output of such decoder 36, the output of the AND circuit 58 becomes high level when the lower 5 bits are 
     
         (b4,b3,b2,b1,b0)=(1,0,0,0,0)                               (2) 
    
     and this case corresponds to 16 in decimal notation. 
     FIGS. 16(1)-16(5) are timing charts to explain the operation of this embodiment. Referring now to these drawings together, the operation of this embodiment is described below. The symbols (1) and (2) and so forth in FIG. 16 indicate the processing steps which are the same as those in the prior art. In the reading cycle SR started from time t11 in FIG. 4, (1) first the control signal R/W is set to a high level, and it is instructed to read out the data from the processor 22. Next, as shown in FIG. 16 (1), the chip select signal CS is set to a low level, and the processor 22 is selected. 
     (3) The arithmetic control device 21, as shown in FIG. 16 (4), starts to transfer the address in which the data to be read in the processor 22 is stored, to the processor 22. Here (4) the processor 22 set the transfer permit signal TE  to a high level as shown in FIG. 16 (3), and the transfer from the processor 22 is prohibited. When transfer of the address data 63 is over, the processor 22 reads out the internal data of the address, and when the output to the arithmetic control device 21 is over, (5) at time t12, the transfer permit signal TE is set to a low level, and the transfer prohibit state is canceled. 
     (6) On the basis of the clock signal CK from the arithmetic control device 21, (6) as shown in FIG. 16 (5), the data is read out from the processor 22 to the arithmetic control device 21. When the data transfer is over, (8) at time t13, the transfer permit signal e,ovs/TE/  is set to a low level, and the transfer prohibit state is canceled again. This ends the data reading processing. 
     In the writing cycle SW, (9) the control signal R/W set to a low level, and the writing action from the arithmetic control device 21 to the processor 22 is indicated. 
     (10) Next, as shown in FIG. 16 (4), the arithmetic control device 21 sends out (11) the address data 65 in succession to the main body data 64 to be stored in the processor 22. (12) When send-out of the address data 65 is started, the transfer permit signal e,ovs/TE/  becomes a high level at the processor 22 side, and the transfer is prohibited. (13) When the transfer of the address data 65 is over and writing into the specified address of the internal memory is over, the transfer permit signal e,ovs/TE/  becomes a low level, and the transfer is ready. 
     (14) Sequentially, at the arithmetic control device 21 side, the chip select signal e,ovs/CS/  is set to a high level, and data writing is finished. 
     At this time, as shown in FIG. 13, while the control signal R/W is high level, the AND circuit 38 is selected. In order words, in order to transfer data, the clock signals delivered from the arithmetic control device 21 are counted by the binary counter 34, and its output is delivered to the decoders 35 and 36 as explained by reference to FIG. 14 and FIG. 15. During the period of reading cycle SR, the decoder 36 is selected by the AND circuit 38, and when the binary counter 34 counts 16 bits as explained in relation to FIG. 15, the output of the AND circuit 58 is changed to the high level, and the data is latched into the buffer register 28. 
     FIGS. 17(1)-17(2) show the setting state of the address and data in the register, in which FIG. 17 (1) indicates the data reading mode, and FIG. 17 (2) denotes the data writing mode. 
     In this way, when transferring the address from the address register 25 to the buffer register 29, it is enough to read out always from the same position, and changeover circuit or the like is not necessary. 
     At this time, when there are only 16 bits as mentioned above, the address data 63 is only transferred, and the address data stored in the address register 25 is latched in the address register 29 of the buffer register 28. By the thus latched address data, the reading of the internal memory after time t12 is effected. 
     In the writing cycle SW, on the other hand, the control signal R/W is at a low level, and the decoder 35 is selected by the AND circuit 37. At this time, when counting of 40 bits is finished by the binary counter 34, a latch control signal is delivered to the buffer register 28. Such a case corresponds to the transfer of the main body data 64 and address data 65 after time t3 in FIG. 16, and when the transfer of such address data 65 is over, the latching action from the transfer register 27 to the buffer register 28 is effected. 
     By this embodiment, as obvious from the description herein, the command 15 explained in the prior art may be deleted from the transfer data, and the dummy main body data 17 may be also eliminated. Hence, the data length necessary for transfer is outstandingly shortened, and the transfer speed is increased, while the transfer efficiency is notably enhanced. 
     The composition of the decoders 35 and 36 is, however, not limited to the configurations shown in FIG. 14 and FIG. 15. 
     Thus, according to this invention, the reading action and writing action carried out between the control device and the processor may be distinguished only by the level of the signal line, without having to send the corresponding commands to each other. Besides, when transferring an address from the transfer register to the buffer register, it is enough to only read out from the same position, and hardware for changeover is not needed, and the construction may be simplified. Furthermore, the data length responsible for transfer may be reduced, and the data may be transferred efficiently, while the transfer speed may be superbly increased. 
     FIG. 18 is a block diagram of another embodiment of the present invention. By the command from a first processor U1, (a) the data stored in the storage region of memory M1 provided in a second processor U2 is read out, and is received by the first processor U1, or (b) the data from the first processor U1 may be written into the storage region of the memory M1. From the transmitting register TX1 of the first processor U1, various sets of combined uniform A to E consisting of a total of 24 bits in the unit of 8 bits each are sequentially output to the receiving register RX2 of the second processor U2 through line 16. From the transmitting register TX2 of the second processor U2, the data is output sequentially bit by bit to the receiving register RX1 of the first processor U1 by way of line 17. 
     FIGS. 19(1)-19(3) show a diagram of the composition of combined information sets A to C which are led out into the line 16 when the data is written into the memory M1 of the second processor U2 from the first processor U1. When writing data from the first processor U1 into the memory M1 of the second processor U2, to begin with, the first combined information A is output from the first processor U1 as shown in FIG. 19 (1). In this information A, the first bit a1 is a redundancy indicated by the * mark, the second bit a2 is 0 which is a write command to instruct to write the data, and the third bit a3 to the 24th bit a24 are the address information for specifying the first storage region address to be written in. 
     In succession, from the first processor U1, the second combined information B is sent out as indicated in FIG. 19 (2). In this information B, the first bit b1 is a continued write command, which is 1 to express to continue to write in FIG. 19 (2), the second bit b2 is the * mark to express the redundancy, and the third bit b3 to the 24th bit b24 denote the first data to be written in the memory M1. Such second combined information B is sent out repeatedly by the number of data sets, and in the information C including the final n-th data indicated in FIG. 19 (3), the first bit c1 is 0 to express stopping of the writing action, the second bit c2 is the * mark to denote redundancy, and the third bit c3 to the 24th bit c24 are the n-th data to be written in. If the data sent out from the first processor U1 is only one, after the information A is sent out, the information C is sent out, and the writing action is terminated. 
     When reading out the data stored in the memory M1 of the second processor U2 into the first processor U1, the third combined information D is sent out as indicated in FIG. 20 (1) from the first processor U1. In this information D, the first bit d1 is a block transfer command to indicate whether or not the block transfer for sequentially reading out from the storage region possessing plural addresses each, the second bit d2 is 1 which is a reading command to instruct to read out the data, and when the first bit d1 is 1 as shown in FIG. 20 (1), it is regarded as block transfer, and the data is sequentially read out from the storage region of the address specified by the address information of the third bit d3 to the 24th bit d24. 
     When the first bit d1 of this information D is 1, that is, when it is a block transfer, the fourth combined information E shown in FIG. 20 (2) is output in succession to the information D from the first processor U1. In this information E, the first and second bits e1, e2 are the * mark to denote the redundancy, and the third bit e3 to the 24th bit e24 are the word number information to express the number of words of the data to be read. Therefore, the data is sequentially read out from the memory M1 by the number of words expressed by the word number information of information E, starting from the storage region in which the address is specified by the address information of information D. 
     In this way, the 24-bit information sets A to E are output from the first processor U1 to the second processor U2. Of these 24 bits, the first two bits are a command to express reading or writing as mentioned above, and this command is given to the command decoder 19 through the line 18. In the remaining 22 bits of the receiving register RX2, the address information for reading and writing, or the data to be written or the word number information to read out is stored. 
     The address information stored in the receiving register RX2 is supplied to the address decoder 20 through the line 29, and the address is specified in the storage region in the memory M1. In relation to the address decoder 20, a counter 28 is provided, and this counter 28 specifies the address by incrementing sequentially every time the data is written or read, from the first address specified by the address information. 
     The data stored in the receiving register RX2 is fed to the memory M1 from the line 21, and data is stored in the storage region specified by the address decoder 20. 
     The word number information stored in the receiving register RX2 is given to the counter 26 through the line 30, and the counter 26 stores this word number information as the counting, and every time the data is read out, the counting is decremented until zero, when the signal is output to the control circuit 23 through the line 27, and the data reading action is stopped. 
     When reading out data from the memory M1 and transferring to the first processor U1, the data stored in the storage region in the memory M1 in which the address is specified by the signal from the address decoder 20 is supplied to the transmitting register TX2, and the content of this transmitting register TX2 is transferred to the receiving register RX1 of the first processor U1 through the line 17. 
     The registers TX1 and RX1 in the first processor U1 are controlled by the control circuit 22. A control circuit 23 is similarly provided in the second processor U2. This control circuit 23 controls the address decoder 20 and the memory M1 in response to the signal from the command decoder 19, and a control signal TE is sent out to the control circuit 22 by way of line 24, while the control signal CS is received from the control circuit 22 through line 25. 
     FIGS. 21(1)-21(5) are waveform diagrams to explain the operation of the embodiment shown in FIG. 18, and FIG. 22 is a flowchart for explaining its operation. Incidentally, the operation conforming to the flowchart in FIG. 22 is realized by hardware. At step n1, if the control signal CS is a logic 1, the operation advances to step n2, and the transfer block is reset to return to the initial state. At step n1, therefore, a determination is made as to whether or not the control signal CS by way of line 25 is a logic 0, and this control signal CS is indicated in FIG. 21 (1), and when it is judged to be of a low level, it means that it is necessary to transfer the information A to E to the second processor U2 from the first processor U1, and the operation goes to step n3. Here, the control signal TE, which is a logic 0, is supplied to the control circuit 22 from the control circuit 23 by way of line 24. The control signal TE is a signal for permitting transfer of information A to E, which is shown in FIG. 21 (2). 
     At step n4, the first or third combined information A and D is sequentially transferred bit by bit from the transmitting register TX1 of the first processor U1 to the receiving register RX2 of the second processor U2 through line 16, in synchronism with the clock signal indicated in FIG. 21 (5). Thus, as shown in FIG. 21 (3), information A and D are sequentially stored in the receiving register RX2 as 8-bit signals S1, S2, and S3. Of the first 8-bit signal S1, the first two bits are a reading or writing command as stated above, and the remaining 6 bits of the signal S1, and the other two signals S2 and S3 are address information in a total of 22 bits for specifying the address the store region in the memory M1. 
     After the signal is stored in the receiving register RX2, internal arithmetic processing is effected in the second processor U2. 
     At step n5, the second bit a2 or d2 of the fist or third combined information A or D being received is decoded by the command decoder 19, and is fed to the control circuit 23. At step n6, the address information stored in the receiving register RX2 is decoded by the address decoder 20. At step n7, the command decoded at step n5 is judged to be either a writing or a reading command. 
     At step n7, when the command is judged to be a data writing command, the operation goes to stop n8, and the control signal TE is set to logic 0 as shown in FIG. 21 (2), and the second combined information B and C composed of 8-bit signals S11, S12, and S13 is received as shown in FIG. 21 (4), and at step n9 the data contained in the third bit b3 and c3 to the 24th bit b24 and c24 of thus received information B and C is written into the storage region of the address which is decoded by the memory M1. At step n10, a determination is made as to whether or not to continue writing from the first bit b1 and c1 of the information B and C, and if yes, at step n11, the address of the address decoder 20 is incremented by the counter 28, thereby returning to step n8, and data writing is continued. If a determination is made to stop writing at step n10, the operation returns to step n1. 
     At step n7, if the data reading command is identified, the operation advances to step n12, and the counter 26 is cleared. At step n13, a determination is made as to whether or not to transfer block from the first bit d1 of the information D, and if yes, that is, if the first bit d1 is 1, at step n14, the control signal TE is set to a logic 0 as shown in FIG. 21 (2), and the fourth combined information E composed of 8-bit signals S11, S12, and S13 is received as shown in FIG. 21 (4), and the operation advances to step n15. In step n13, if it is judged not to be a block transfer, that is, if the first bit d1 is 0, the operation directly goes to step n15. At step n15, the data in the storage region of the memory M1 in which the address is specified is stored in the transmitting register TX2 and is set. At step n16, the data for one word portion is transferred from the transmitting register TX2 to the receiving register RX1, and at step n17 a determination is made as to whether or not the counting of the counter 26 is zero. If not zero, the operation advances to step n18, and the counter 26 is decremented, and the address is incremented at step 19, thereby returning to step n15. At step n17, if the counting of the counter 26 is zero, the operation return to step n1. 
     In this embodiment, as described herein, when writing plural data from the first processor U1 into the memory M1 of the second processor U2, the first processor U1 is not required to send out the address information for every data to be written, and the second process U2 is required only to write in the data sequentially until the continued write command shows stopping of the writing action. Therefore, the quantity of address information to be sent out from the first processor U1 to the second processor U2 may be saved, and the data writing speed may be enhanced. Similarly, when reading out data from the memory M1 of the second processor U2 into the first processor U1, it is not necessary to send out the address information for every data to be read out, and the second processor U2 has only to read out the data sequentially by the number of words expressed by the word number information, so that the reading speed may be enhanced. Furthermore, since these processings are realized by the hardware, the period will not be come short for digital signal processing in every sampling period as mentioned in relation to the background technology, and it is not needed to extend the sampling period, so that the quality of signal processing may be favorably maintained. 
     According to the present invention, as understood from the above description, when writing plural sets of data from the first processor to the second processor, or when reading out from the second processor to the first processor, it is not necessary to send out the address information for every data to be written or read, and the data writing or reading speed may be enhanced, and the time for digital signal processing may be increased. 
     FIG. 23 is a block diagram of a main embodiment of the present invention. The data is sequentially transferred in series bits, from a processor A to another processor B. The processor A is provided with a transmitting means 8, and the other processor B has a receiving means 9. The data to be transmitted at the transmitting means 8 is stored in first transmitting registers A1 to An in a total number of n, and the store cell of each bit is indicated by reference code all, a12, a13 . . . ; a21, a22, a23, . . . ; to an1, an2, an3, . . . The data of every bit from these transmitting registers Al to An are sequentially transferred to the receiving means 9 from the line --  1 through OR gate G1. In these transmitting registers Al to An, signals for synchronizing are fed from the first n cells CAl to CAn of the shift register CA. 
     From the clock signal generator circuit 10 to line MCLK, a clock signal of a predetermined specified period is given. This clock signal generator circuit 10 outputs one clock signal once in every n times of the clock signal MCLK to the line CK1, and feeds it to the shift register CA. The shift register CA, responding to the clock signal by way of line CK1, sets the first cell CAl to a logic 1, and the remaining store cells CA2 to CAn to a logic 0. Besides, responding to the clock signal by way of the line MCLK, the shift register CA sequentially moves the single store cells CAl to CAn of which are at a logic 1. This shift register CA does not return the initial cell CAl to a logic 1, if more than n clock signals are entered from the line MCLK, as long as clock signal is not entered through line CK1, and in the period while the clock signals through the line MCLK are being fed by the number exceeding the plurality n as mentioned above, all cells CAl to CAn remain at a logic 0 unless the clock signals are fed from the line CK1. In the explanation to follow, the reference codes MCLK and CK1 denote the lines, and may also indicate the clock signals by way of such lines. 
     At the receiving means 9, second m receiving registers Bl to Bm are provided, and data are commonly supplied to these receiving registers Bl to Bm by way of line l1. This shift register CB possesses a structure similar to that of the above shift register CA, and also has cells CBl to CBm. When the logic 1 signals from these cells CBl to CBm are respectively supplied to the corresponding receiving registers Bl to Bm, the store contents of the cells b11, b12, b13, . . . ; b21, b22, b23, . . . ; b31, b32,b33, . . . ; bm1, bm2, bm3, . . . are fed to the receiving registers Bl to Bm bit by bit. In the shift register CB, clock signals MCLK, CK1 from the clock signal generator circuit 10 are respectively supplied. 
     Referring now to FIGS. 24(1)-24(6), the operation when the first plural number n and second plural number m are equal to each other (n=m) is explained below. FIG. 24 (1) shows the sequential data of the bits which are output to the line l1 through the OR gate G1 from transmitting registers Al to An of the processor A. Such data is output in synchronism with the clock signal MCLK shown in FIG. 24 (2). The clock signal CK1, as shown in FIG. 24 (3), is generated at every plural n (=m) clock signals MCLK. To the cells CA1, CA2, and CA3 of the shift register CA to the transmitting registers A1, A2, and A3, transmission signals T1a, T2a, and T3a are sequentially output as shown in FIGS. 24 (4), 24 (5), and 24 (6), and these signals T1a, T2a, and T3a correspond to that fact that the contents of the cells CA1, CA2, and CA3 are a logic 1, and a similar operation is conducted thereafter. Thus, over a whole cycle W, the contents of the first cells all, a21, a31, . . . , an1 of the transmitting registers Al to An are output. In the subsequent cycles, the data from the second cells a12, a22, a32, . . . , an2 of the transmitting registers Al to An are sequentially output. Repeating such operation, the contents of the transmitting registers Al to An are output to line l1, and transferred. 
     At the processor B, in the receiving means 9, reception to the cells of the receiving registers Bl to Bm is effected on the basis of the output from one cell which is at a logic 1 out of the cells CBl to CBm of the shift register CB. In other words, the transmitting register Al corresponds to the reception register B1, and the content of the cell all is transferred to the cell b11 and stored, while the content of the cell a21 of the transmitting register A2 is transferred to the cell b21 of the receiving register B2 to be stored. Thereafter, similarly, the content of the cell anl of the transmitting register An is stored in the cell bml of the receiving register Bm. In this way, the data transfer of one cycle is over. 
     Here, a clock signal CK1 is generated, and the first transmitting register A1 and receiving register B1 of the next cycle correspond to each other, and thereafter the contents of the cells a12, a22, . . . , an2 of the transmitting registers A1, A2 . . . , An are sequentially stored in the cells b12, b22, . . . , bm2 of the receiving registers B1, B2, . . . , Bm. 
     FIGS. 25(1)-25(8) are drawings to explain the operation when the first plural number n is less than the second plural number (n&lt;m). As shown in FIG. 25 (1), from the transmitting registers Al to An to line Λl, the data of cells a11, a21, . . . , and of each stage are sequentially output. In the period while the clock signals MCLK shown in FIG. 25 (3) are being generated over the plural number n, data is not output on line Λl. At the receiving means 9, reception of data to the first stage cells bll to bml of the receiving registers Bl to Bm of second plural number m is realized as shown in FIG. 25 (2), in response to the clock signal MCLK. 
     Every time a clock signal MCLK of a plural number m is generated, one clock signal CKl is generated, which causes to transfer the data of the next cycle. The waveform of clock signal CKl is as shown in FIG. 25 (4). Of the signals being output from cells CBl to CBm of the shift register CB, those representatively indicated by reference CB, those representatively indicated by reference codes T1b, T2b, T3b, . . . , Tmb are respectively shown in FIG. 25 (5), 25 (6), 25 (7) and 25 (8). 
     FIGS. 26(1)-26(8) are drawings to explain the operation when the first plural number n exceeds the second plural number (n&gt;m). From the transmitting means 8, the bit-sequential data as shown in FIG. 26(1) is transferred to line l1. At the receiving means 9, the data can be stored to the first stage cells b11, 2b1, . . . , bm1 of the receiving registers Bl to Bm as shown in FIG. 26(2), and if a clock signal MCLK shown in FIG. 26 (3) is further supplied later, storing in the receiving registers Bl to Bm in that cycle will not be enabled. The clock signal CLK is generated upon every generation of clock signal MCLK of very first plural number n as shown in FIG. 26(4). In this way, the signal of a logic 1 is sequentially output to cells CAl to CAn of the shift register CA of the transmitting means 8 as shown in FIG. 26(5), 26(6), 26(7) and 26(8), and the data transfer from the first stage cells all, to anl of the transmitting registers Al to An of the first plural number n is finished. In the second cycle, the data is transferred from the second cells a12 to an2 of the transmitting registers Al to An, and is received at the receiving means 9. 
     In a further different embodiment of the present invention, it may be also possible to compose it so that one clock signal CKl may be generated every time pulses of clock signal MCLK are generated by a predetermined number exceeding the first plural number n and second plural number m. 
     FIG. 27 is a block diagram of a still different embodiment of the present invention, in which between the transmitting means 81 and receiving means 91, digital sound signals in a total of two channels of 16 bits each are transferred, and from another transmitting means 82 to receiving means 92, sound signals in a total of four channels of 16 bits each are transferred. Of the four cells of shift register CAa, the first two cells are given to transmitting registers A1a and A2a individually possessing 16 cells corresponding to each one of two channels, and their outputs are respectively supplied to the receiving registers B1a and B2a from the OR gate G2 through line 12. To these receiving registers B1a and B2a are fed signals from the first two cells of the shift register CBa having four cells. 
     The outputs from each cells of shift register CAb at the transmitting means 82 possessing cells corresponding to four channels are fed to the transmitting registers A1b to A4b corresponding to each channel. The transmitting registers A1b to A4b possess 16-bit cells, and their outputs are fed to the receiving registers B1b to B4b of the receiving means 92 by way of line 13 from the OR gate G3. To these receiving registers B1b to B4b are fed signals from the shift register CBb having four cells. Thus, between the transmitting and receiving means 81 and 91, the 2-channel portion of sound signals is transferred, while between the transmitting and receiving means 82 and 92, the sound signals of the 4-channel potion is transferred, and the data transfer periods are identical. 
     The invention may be embodied in a wide range for data transfer. 
     In the above embodiment, the data is output bit by bit from each transmitting register to the receiving register, but in another embodiment of the present invention, it may be also possible to design it to transfer plural bits of each transmitting and receiving register in batches. 
     Thus, according to the present invention, it is possible to transfer various data which are different, for example, in the number of pieces of information, smoothly and in a simple construction. 
     FIG. 28 is a block diagram showing the composition of the receiving side of an embodiment of the present invention, and FIG. 29 is a block diagram showing the composition of its transmitting side. Referring now to FIGS. 28 and 29, the composition of this embodiment is described below. The receiving side shown in FIG. 28 of this embodiment comprises a transfer register 45 composed of four shift registers, for example, 41, 42, 43, and 44. This transfer register 45 is composed to posses functions of both transfer registers 1 and 21 and buffer registers 2 and 22 as explained in relation to the prior art later. 
     Between shift registers 41 and 42, and 43 add 44, changeover switches 46 and 47 are disposed, and they are connected to another changeover switch 49 provided in the receiving line 48 for receiving the transfer data. A data bus 50 is connected to the transfer register 45. 
     The structure of the transmitting side in FIG. 29 is similar to the receiving side shown in FIG. 28, comprising, for example, a transfer register 55 composed of four shift registers 51, 52, 53, and 54, changeover switches 56 and 57 disposed between the shift register 51 and 52, and 53 and 54, and a changeover switch 59 connected between these changeover switches 56 and 7 and the transmission line 58. 
     The changeover switches 46 and 47 are controlled by a clock signal CK3 which is described later, and the shift action of the shift registers 41 to 44 is executed by the internal clock signal CK3 generated inside. The switching action of the changeover switch 49 is realized by a synchronous signal SY1 which is described later. 
     The changeover switches 56 and 57 are controlled by the clock signals CK3 supplied to the shift registers 51 to 54 and the changeover switch 59 is controlled by the synchronous signal SY1 mentioned later. 
     FIGS. 30(1)-30(6) are timing charts for explaining the operation of this embodiment. Referring also to FIGS. 30(1)-30(6), the operation of this embodiment is described below. First, the receiving action of this embodiment is narrated. When the transfer data to be received reaches the reception line 48, the changeover switch 49 is alternately changed to the changeover switches 46 and 47 in every half period relative to the period W1 of the synchronous signal SY1 as shown in FIG. 30 (1). While the changeover switch 49 is selected at the switch 46 side, the changeover switch 46 changes over at the rise timing and fall timing of the clock signal CK3 shown in FIG. 30 (4), and the transfer data on the reception line 48 is stored in the shift registers 41 and 42, bit by bit at the rise of the clock signal CK4 generated inside. 
     In this way, in half period of synchronous signal SY1, data 1 and 2 are transferred to the shift registers 41 and 42 as shown in FIG. 30 (2) and (3), and at time t3 in FIG. 30 (1) the changeover switch 49 is selected to the switch 47 side, and data 3 and 4 are written into the shift registers 43 and 44 in the same manner. 
     This time, the transfer register 45 is connected to the data bus 50, and therefore in the first half period W1a in FIG. 30 (1) while data is transferred to the shift registers 41 and 42, if there is data already stored in the shift registers 43 and 44, the operator can freely access the data through the data bus 50. In the second half period W1b in FIG. 30 (1), the same operation is effected on the shift registers 41 and 42. That is, in the receiving action of the embodiment, different registers are used for data access in parallel to the receiving action. 
     The transmitting action is next shown. In this case, too, the operation is basically same as the receiving action. The data 1 to 4 is to be transmitted is stored in the shift registers 51 to 54 through data bus 50, and at time t4 in FIG. 30 the changeover switch 59 is, for example, to the changeover switch 57 side, when the changeover switch 57 is alternately changed to the shift registers 53 and 5 by the clock signal CK3, so that the contents in the shift registers 53 and 54 are read out bit by bit at every rise and fall of CLK4 similarly. At time t3 in FIG. 30, when this reading action is finished, the changeover switch 59 is changed to the switch 56 side, and by the operation of the changeover switch 56 same as that of the changeover switch 57, the memory contents in the shift registers 51 and 52 are output to the transmission line 58. 
     While the contents in the shift registers 53 and 54 are being transmitted, the contents in the shift registers 51 and 52 where data 1 and 2 are stored can be freely accessed through the data bus 50. While the contents in the shift registers 51 and 52 are being transmitted, of course, the same processing is done on the memory contents of the shift registers 53 and 54. 
     In this embodiment, thus, parallel to the transmission/reception action of transfer data, during the period of transmission/reception of the data to be transferred, the remaining data may be freely read out or written in. As a result, the composition of, for example, processor, is notably simplified. 
     In this way, according to the present invention, when transferring data, it is not necessary to prepare the shift register group for temporarily storing the data to be transferred in the same number as the shift register group responsible for transfer, and the construction may be notably simplified. 
     FIG. 31 is a block diagram of a processor in an embodiment, in which a sound signal processor 13 is used as an example. The analog sound signals of right and left channels to be fed in input terminal T are converted into digital sound signals of two channels in an analog/digital converter circuit 14, and are fed to a processor DSP1 through line 15. At this processor DSP1, for example, tone control is executed. The output of the processor DSP1 is fed to a processor DSP2 through line 16. 
     At this processor DSP2, the sound signals in two channels fed from the line 16 are further processed digitally, and in order to enhance the presence as in the sound system, sound signals in four channels are produced in order to deliver them to speakers disposed at the front left side FL, front right side FR, rear left side RL, and rear right side RR, and the sound signals of 16 bits each of the front left and right sides FL and FR are stored in series in the shift register 17, while the sound signals of the rear left and right sides RL and RR are stored in the other shift register 18. In the shift registers 17 and 18, the speaker configuration and the corresponding digital sound signals are represented by the same reference codes FL, FR; RL, and RR. 
     From the clock signal generator 19, a first clock signal CLK1 having a predetermined specific frequency shown in FIG. 32 (1) is led out into the line 20, and is fed as an external clock signal to the input terminal 21 of the processor DSP2. This external clock signal CLK1 is supplied to the frequency converter circuit 22 disposed in the processor DSP2. This frequency converter circuit 22 is, for example, composed of a monostable multivibrator, and supplies a clock signal having double the frequency of the external clock signal CLK1 as shown in FIG. 32 (2) into the clock selection circuit 33 though the line 23, in response to rise and fall of the external clock signal CLK1 fed to the input terminal 21. The external clock signal CLK1 fed to the input terminal 21 is also supplied to the clock selection circuit 33 directly through line 24. A clock signal generator circuit 34 is composed of the frequency converter circuit 22 and clock selection circuit 33. 
     The clock selection circuit 33 changes over and outputs the clock signal through line 23 and external clock signal CLK1 through line 24, in response to the voltage level of the control terminal 35. At the control terminal 35, an output from the control input circuit 36 is given, and this control input circuit 36 is composed of resistance 37 and switch 38, and one of the terminals of the resistance 37 is connected to the high level power source, while the other terminal is connected to one of the contacts of the switch 38. The other contact of the switch 38 is grounded. In this way, the potential at the connection point of the resistance 37 and switch 38 is fed to the clock selection circuit 33 through control terminal 35. 
     Therefore, when a control signal as shown in FIG. 32 (3) is entered from the control terminal 35, the clock selection circuit 33 feeds the clock signal shown in FIG. 32 (4) to the changeover control circuit 25. The changeover control circuit 25, corresponding to the input clock signal, outputs the changeover circuits of mutually reverse polarities as shown in FIG. 32 (5), (6) to the line 26 and line 27. 
     The changeover signal coming out to the line 26 is also fed to the shift register 17 and to the AND gate G1. The changeover signal outputted to the line 27 is supplied to the shift register 18 and the other AND gate G2. The shift register 17, responding to the changeover signal from the line 26, sequentially outputs bit by bit the sound signals of 16 bits each of the front left and right side FL and FR stored therein as shown in FIG. 32 (7). 
     Likewise, the shift register 18, responding to the changeover signal from the line 27, sequentially outputs bit by bit the sound signals of 16 bits each of the rear left and right side RL and RR as shown in FIG. 32 (8). What is indicated by FL1 to FL4 in FIG. 32 (7) represents the data of the first to fourth bit of the sound signal of the front left side FL, and similarly what is indicated by RL1 to RL3 in FIG. 32 (8) denotes the data of the first to the third bit of the sound signal of the rear left side RL. 
     The sound signals of each bit from the shift registers 17 and 18 are respectively supplied to the AND gates G1 and G2. The sound signals from the AND gates GI and G2 are respectively fed to two digital/analog converter circuits 30 and 31 through the output terminal 28 and line 29 from the OR gate G3. The digital signal output from the output terminal 28 is as shown in FIG. 32 (9). In this way, responding to the external clock signal CLK1 supplied to the input terminal 21, the sound signal stored in the shift registers 17 and 18 is sequentially output in series alternately bit by bit from the output terminal 28. 
     The clock signal from the clock signal generating circuit 19 is directly supplied to the digital/analog converter circuit 30 from the line 20, and is also output to the other digital/analog converter circuit 31 through the inverter circuit N1. The digital/analog converter circuits 30 and 31 are identical in structure. The digital/analog converter circuit 30 responds to the rise of the external clock signal CLK1 as shown in FIG. 32 (1) through the line 20, and receives and stores the sound signal through the line 29 bit by bit. 
     Therefore, the digital/analog converter circuit 30 receives only the sound signal stored in the shift register 17 indicated by reference codes FL1, FL2, and FL3, and so forth, out of the digital sound signals on the line 29 shown in FIG. 32 (9), sequentially bit by bit, and converts it into analog sound signal in a total of two channels of the front left and right side FL, FR, and leads out. 
     The other digital/analog converter circuit 31, responding to the rise of the clock signal through the inverter circuit N1, receives only the sound signal stored in the shift register 18 indicated by reference codes RL, RL2, and RL9, and so forth, out of the sound signals shown in FIG. 32 (9), sequentially bit by bit, and converts it into an analog sound signal in a total of two channels of the rear left and right side RL and RR, and outputs it. For the sake of simplicity of explanation, here, an example of using clocks of the same frequency is demonstrated, but usually when the control input is of a low level, multiple data can be transferred by a clock input at a faster speed. 
     In this way, while a clock signal from the frequency converter circuit 22 is supplied to the changeover control circuit 25, the shift registers 17 and 18 can transfer the data into the digital/analog converter circuits 30 and 31 at double the frequency of the external clock signal CLK1 from the clock signal generator circuit 19, and the sound signals for the portion of 4 channels can be transferred to using a same external clock signal CLK1 as the two-channel sound signal through the lines 15 and 16. 
     In a special state of use such as when debugging, a high-speed second external clock signal CLK2 is issued from the clock signal generator circuit 19 as shown in FIG. 33 (1). At this time, the clock signal from the frequency converter circuit 22 cannot follow such a rapid external clock signal CLK2 due to the effects of the circuit constant elements or the like, and therefore, by operating the switch 38 to output this external clock signal CLK2 through the line 24 from the clock selection circuit 33, the data can be transferred securely as shown in FIG. 33 (2) without causing transfer errors or other trouble. 
     Thus, in this sound signal processor 13, external clock signals CLK1 and CLK2 from the clock signal generator circuit 19 through the line 24, and the clock signal having double the frequency of the external clock signal CLK1 from the frequency converter circuit 22 through the line 23 are changed over by the clock selection circuit 33, and are used as an internal clock signal in the processor DSP2, and therefore the data can be transferred at double the frequency of the external clock signal CLK1, and moreover in a special state of use such as when debugging, data can be transferred in correspondence with the high speed external clock signal CLK2. 
     The invention may be embodied not only for the processing of sound signals, but also widely in other technical fields. Instead of the digital/analog converter circuits 30 and 31, circuits having constructions for other digital signal processings may be employed. 
     According to the present invention, as clear herein, the output data from the first processor may be alternately transferred to two second processors in a simple structure. Besides, since it is designed to output by changing over the external clock signal and the clock signal from the frequency converter means by the use of the clock selection means, the processing circuit can, for example, process arithmetically or transfer data at a speed of desired times the external clock while responding to the external clock signal, on the basis of the clock signal generated by the frequency converter means, and can also process according to the clock signal when the frequency of the external clock signal is changed. 
     FIG. 34 is a block diagram showing the composition of the transmission side according to an embodiment of the present invention, and FIG. 35 is a block diagram showing the composition of the reception side thereof. In this embodiment, the group data composed of two-word data is transferred, and the one-word data contains, for example, 32 bits. In the composition of the transmission side shown in FIG. 34, there is contained, for example, a transfer register 44 composed of shift registers 41, 42, and 43 possessing a capacity of 32 bits each. This transfer register 44 is composed so as to contain the functions of both buffer register 22 and transfer register 21 as explained in relation to the background technology as mentioned later. 
     To the transfer register 44, a parallel signal is entered from the data bus 47 through changeover switches 45 and 46 which are the second switching means. The shift registers 41 to 43 contained in the transfer register 44 are connected to the transmission line 49 for transmitting serial signals through the changeover switch 48 which is the first switching means. 
     The changeover switch 48 has input terminals 48a, 48b, and 48c, and the shift registers 41, 42, and 43 are respectively connected to these input terminals. Switching of the changeover switch 48 is based on the synchronous signal SY1 which is mentioned later, and serial signals delivered by the shift registers 41 to 43 are selectively output to the transmission line 49 as a result of this switching. 
     The changeover switches 45 and 46 respectively possess output terminals 45a, 45b, and 45c; and 46a, 46b, and 46c. The output terminals 45a and 46a are connected to the shift register 41, and the output terminals 45b and 46b are connected to the shift register 42, and the output terminals 45c and 46c are connected to the shift register 43. Changeover switches 45 and 46 changeover as shown below on the basis of the synchronous signal SY1, so that the parallel inputs from the data bus 47 may be selectively fed to the shift registers 41 to 43. 
     Referring next to FIG. 35, the structure of the receiving side is explained below. The composition of the receiving side shown in FIG. 2 is similar to that of the transmission side shown in FIG. 34, and it contains a transfer register 53 composed of shift registers 57, 58 and 59. To the shift registers 57 to 59, serial signals are selectively entered from the reception line 54 for receiving serial data through the changeover switch 51 which is the first switching means. The shift registers 57 to 59 are connected to the data bus 60 through changeover switches 55 and 56 which are second switching means. 
     The changeover switch 51 possesses output terminals 51a, 51b, and 51c, and these output terminals are respectively connected to the shift registers 57, 58, and 59. The switching action of the changeover switch 51 is based on the synchronous signal SY1, and as a result the serial data through the reception line 54 is selectively entered into the shift registers 57 to 59. 
     The changeover switches 55 and 56 possess input terminals 55a, 55b, and 55c; and 56a, 56b, and 56c. The input terminals 55a and 56a are connected to the shift register 57, and the input terminals 55b and 56b are connected to the shift register 58, and input terminals 55c and 56c are connected to the shift register 59. The switching action of the changeover switches 55 and 56 is based on the synchronous signal SY1, and as a result the parallel data is selectively supplied to the data bus 60 from the shift registers 57 to 59. 
     Clock signals CK1 are supplied to the shift registers 41, 42, and 43 in the composition of the above transmission side and shift registers 57, 58, and 59 in the composition of the reception side, which realizes the shift action. 
     FIGS. 36(1)-36(7) are timing charts for explaining the data transfer action in the above composition. FIG. 36 (1) shows the synchronous signal SY1, and FIG. 36 (2) indicates the data to be given to the data bus 60 in each period, and FIG. 36 (3) to (5) respectively represent the state of changeover switches 45 (55), 45 (56), and 48 (51). Furthermore, FIG. 36 (6) indicates the clock signal CK1 and FIG. 36 (7) shows the data to be output to the transmission line 49 (reception line 54). In FIG. 36 (1), the reading of data into the transfer register 44 is indicated by the upward arrow. In FIG. 36 (3) to 36 (5), the input (output) terminals selected by the individual changeover switches are shown, and the input (output) terminals connected to the shift registers 41 and 57 are represented by reference code a, and the input (output) terminals connected to the shift registers 42 and 58 represented by reference code b, and the input (output) terminals connected to the shift registers 43 and 59 represented by reference code c. 
     Now, referring to FIGS. 34 and 36 (7), the operation at the transmission side is explained below. At time T1, in the changeover switch 48, its input terminal is changed from 48b to 48c in synchronism with the fall of synchronous signal SY1. At the same time, in the changeover switch 45, its output terminal is changed from the output terminal 45b to 45a, and in the changeover switch 46, its output terminal is changed from 46c to 46b. At this time, the shift register 41 and shift register 42 are connected to the data bus 47, and data D1 and data D2 of 32 bits each are given parallel in 32 bits or in parallel in 16 bits each. At the shift register 43, synchronizing with the clock signal CK1, the data D0 read into the shift register 43 in the period before time T1 is delivered bit by bit. 
     Since the changeover switch 48 is selected at its input terminal 48c as stated above, data D0 is output to the transmission line 49 bit by bit. In this way, the data D0 is transmitted as a serial signal. Such a data transfer is effected in the period from time T1 to time T2 when the synchronous signal SY1 rises. As a result, the 32-bit data D0 is transferred as a serial signal. 
     At time T2, when the synchronous signal SY1 rises, the input terminal of the changeover switch 48 is synchronously changed from 48c to 48a. At this time, the changeover switches 45 and 46 do not change over, but since the parallel data is fed to the shift registers 41 and 42 from the data bus 47, the transfer speed is fast, and when the synchronous signal SY1 rises at time T2, the data D1 and D2 are already stored in the shift registers 41 and 42. In such a state, along with reading of the data D1 from the shift register 41, parallel data will not be supplied to the data bus 47 to the shift register 41. 
     In the period from time T2 till time T3 when the synchronous signal SY1 falls, data D1 is output to the transmission line 49 bit by bit. 
     When the synchronous signal SY1 rises at time T3, in the input terminal of the changeover switch 48 is synchronously changed from 48a to 48b. In the changeover switches 45 and 46, the respective output terminals are changed over from 45a, 46b to 45c and 46a. That is, the changeover switch 45, in synchronism with the fall of the synchronous signal SY1, has its output terminal changed over from 45a to 45c to 45b and to 45a, and the changeover switch 46, in synchronism with the fall of the synchronous signal SY1, has its output terminal changed over from 46b to 46a to 46c and to 46b. The changeover switch 48, in synchronism with the rise and fall of the synchronous signal SY1, has its output terminal changed over from 48c to 48a to 48b and to 48c. In this way, in the period of data read-out from any one of the shift registers, the data is fed to the other two shift registers from the data bus 47, and in the period from time T1 to time T3, serial data of 64 bits will be output to the transmission line 49. 
     In the period from time T3, data D3 and D4 are read parallel to the shift registers 43 and 41 from the data bus 47. The shift register 42 is, at this time, connected to the transmission line 49, and the data D2 which is its memory content is delivered bit by bit. 
     Referring next to FIGS. 35 and 36 (7), the operation at the reception side is explained. To the reception line 54, the serial data as shown in FIG. 36 (7) is transmitted. At this time, the output terminal of the changeover switch 51 is changed over as shown in FIG. 36 (5), and the switching action of the input terminal at changeover switches 55 and 56 becomes as shown in FIG. 36 (3) and 36 (4). 
     In the period from time T1 to time T2, since the output of the changeover switch 51 is selected by 51c, the serial data reaching the reception line 54 is fed to the shift register 59. The input serial data is read to the shift register 59 bit by bit by the clock signal generated inside the transfer register 53. In this way, the 32-bit data D0 is read to the shift register 59 in the period from time T1 to time T2. Thus, the data D0 is held inside the shift register 59 at time T2. 
     In the period from T1 to T2, the shift registers 57 and 58 are connected to the data bus 60, and the data Da and Db entered in the shift registers 57 and 58 before time T1 are fed to the data bus 60 in a relatively short time after time T1. 
     In the period from time T2 to time T3, since the output terminal of the changeover switch 51 is selected by 51a, the data D1 which is the serial data reaching the reception line 54 is fed to the shift register 57. At this time, the input of the changeover switch 55 is selected by 55a, and the shift register 57 is connected to the data bus 60, but since the data Da taken in before time T1 is fed to the data bus 60 in a relatively short time after T1, the shift register 57 is ready to receive the next data. 
     At time T3, the output terminal of the changeover switch 51 is changed to 51b, and the input terminals of the changeover switches 55 and 56 are respectively changed to 55c and 56a. As a result, in a relatively short period after time T3, the data bus 60 is supplied with the data D0 and D1 held by the shift registers 59 and 57 respectively, and the shift register 58 is supplied with the next data D2, bit by bit. 
     Thus, in this embodiment, at the transmission side transfer register 44, the data held by the shift registers 41, 42, and 43 are selectively output bit by bit to the transmission line 49 by the changeover action of the changeover switch 48. To the remaining two shift registers which are not delivering data at this time, parallel data is fed from the data but 47 in a relatively short time. 
     At the transfer register 53 at the reception side, the serial data reaching the reception line 54 is selectively fed to the shift registers 57, 58, and 59, and the data held by the remaining two shift registers to which the serial data is not fed is fed to the data bus 60 as parallel data. 
     As a result, at the transmission side and reception side, the individually installed registers possess the functions of both buffer register and transfer register as mentioned in relation to the prior art, so that the number of registers may be reduced to 3/4 the number required by the prior art. 
     Besides, generally, in the transfer of group data composed of m word data, 2m registers were needed in the prior art, but in the present invention, only m+1 shift registers are needed, and the number of shift registers is reduced by (m+1)/2m. Hence, the structure necessary for data transfer may be outstandingly simplified. 
     According to the present invention, thereby, in transferring group data composed of m word data, the equivalent functions of 2m registers needed in the prior art may be realized by only m+1 registers, and the umber of required registers is only (m+1)/2m, and the structure for data transfer may be notably simplified. Therefore, the construction will not become too large if the data length to be transferred is very large. 
     FIG. 37 is a block diagram of another embodiment of the present invention. The analog sound signals of right and left channels fed to the input terminal 13 are converted into digital sound signal of two channels in the analog/digital converter circuit 14, and is supplied to the processor DSP1 from line 15. In this processor DSP1, the sound signal of two channels entered through the line 15 is digitally processed, and in order to enhance the presence as in the surround system, the sound signals of four channels to be applied to the speakers disposed at the front left side FL, front right side FR, rear left side RL, and rear right side RR is output to a line 16, and is fed to the first processor DSP2 of the invention. 
     At this processor DSP2, the sound signal of four channels fed from the line 16 is further digitally processed, and the 16-bit sound signals at the front left and right side FL and FR are stored in series into the shift register 17, while the sound signals of the rear left and right side RL and RR are stored in the other shift register 18. At the shift register 17 and 18, the speaker configuration and the corresponding digital sound signals are indicated by the same reference codes FL and FR; and RL and RR. 
     From a clock signal generator circuit 19, a clock signal having a predetermined frequency shown in FIG. 38 (1) is output to a line 20, and is fed to the input terminal 21 of the processor DSP2. This clock signal is fed to a control circuit 22 provided in the processor DSP2. This control circuit 22, responding to the clock signal fed to the input terminal 21, outputs the signal indicated in FIG. 38 (2) to the line 23, while a signal shown in FIG. 38 (2) possessing an inverted waveform of the signal from the line 23 is output to a line 24. Another control circuit 25 receives signals from the lines 23 and 24, and outputs a signal shown in FIG. 38 (4) to a line 26, and also outputs a signal shown in FIG. 38 (5) to a line 27. The signals output from the lines 26 and 27 are synchronized with the clock signal fed to the input terminal 21 and the signals output from these lines 26 and 27 are waveforms of mutually reverse polarity. 
     The signal output from the line 26 is fed to the shift register 17, and is also fed to the AND gate G1. The signal output from the line 27 is fed to the shift register 18, and is also added to another AND gate G2. The shift register 17, responding to the signal from the line 26 as shown in FIG. 38 (6), sequentially outputs the sound signals of 16 bits each of the front left and right side FR and FL stored there bit by bit. Likewise, the shift register 18, responding to the signal from line 27, sequentially outputs the sound signal of 16 bits each of the rear left and right side RL and RR, bit by bit as shown in FIG. 38 (7). In FIG. 38 (6), FL1 to FL6 denote the data of the first to sixth bit of the sound signal of the front left side FL, and in FIG. 38 (7), similarly, RL1 to RL5 represent the data of the first to fifth bit of the sound signal of the rear left side RL. 
     The sound signals of every bit from the shift registers 17 and 18 are fed to AND gates G1 and G2. The sound signals from AND gates G1 and G2 are supplied to two second digital signal processing circuits, digital/analog converter circuits 30 and 31, respectively through output terminal 28 and line 29 from the OR gate G3. The digital signal output from output terminal 28 is as shown in FIG. 38 (8). In this way, responding to the clock signal fed to the input terminal 21, the sound signals stored in the shift registers 17 and 18 are output from the output terminals 28, bit by bit alternately, serially and sequentially. The changeover means is composed of the AND gates G1 and G2. 
     The clock signal from the clock signal generator circuit 19 is directly supplied from the line 20 to the digital/analog converter circuit 30, and is fed to another digital/analog converter circuit 31 by way of an inverter circuit N1. The digital/analog converter circuits 30 and 31 have identical structures. The digital/analog converter circuit 30, responding to the rise of the clock signal indicated in FIG. 38 (1) through line 20, receives and stores the sound signal through line 29 bit by bit. Therefore, the digital/analog converter circuit 30 receives only the sound signal stored in the shift register 17 indicated by reference codes FL1, FL2, FL3, ..., among the digital sound signals on the line 29 indicated in FIG. 38 (8), bit-sequentially, and converts it into an analog sound signal of two channels in total of the front left and left side FL and FR, and outputs the signal. 
     The other digital/analog converter circuit 31, responding to the rise of clock signal through the inverter circuit N1, receives only the sound signal stored in the shift register 18 as indicated by RL1, RL2, RL3, . . . , among the sound signals shown in FIG. 38 (8), bit-sequentially, and converts it into an analog sound signal in a total of two channels of rear left and right side, RL and RR, and outputs the signal. 
     In this way, the sound signal from the output terminal 28 of the processor DSP2 is commonly fed to the two digital/analog converter circuits 30 and 31 connected after the line 29, and the clock signal from the clock generator circuit 19 is supplied to these circuits DSP2; 30 and 31 directly and by way of an inverter circuit N1 to control it. Therefore, the structure may be simplified. 
     The invention may be embodied not only for processing sound signals, but also widely used in other technical fields. Besides, instead of the digital/analog converter circuits 30 and 31, other circuits for digital signal processing may be used. 
     The invention enables, as clear from the description herein, to transfer output data from a first processor to two second processors alternately, and in a simple structure. 
     FIG. 39 is a block diagram showing the structure of a sound signal processor 41 in another embodiment of the present invention. For example, an analog sound signal from a radio receiver is fed to an analog/digital converter 46 from an input terminal 45, and is converted into a digital signal, and is fed into a digital signal processor (hereinafter called processor) 44 composed of large-scale integration or the like. 
     The processor 44 controls the tone, or processes echo or sound signals, for example, by performing arithmetic calculations of input signals such as addition and multiplication, or delaying. The output of the processor 44 is fed to the processor 48 for a different arithmetic processing, and is fed to the digital/analog converter 52 to be converted into an analog signal, which is fed to a power amplifier circuit or the like by way of output terminal 53. 
     The output of the analog/digital converter 46 is composed of 16 bits each of right and left channels per sampling period, in a total of 32 bits of fixed decimal point data as shown in FIG. 40 (1). Digital signal processors 44 and 48, analog/digital converter 46, and digital and analog converter 52 perform an arithmetic operation on the basis of the clock signal SCLK from a clock generator 54 shown in FIG. 40 (2) and synchronous signal SYNC shown in FIG. 40 (3). At the processors 44 and 48, in order to suppress deterioration of dynamic range of S/N ratio due to overflow or underflow during arithmetic operation, the sound signal data is floating decimal point data composed of 16-bit mantissa data shown in FIG. 40 (4) and 4-bit exponent data shown in FIG. 40 (5), and an arithmetic operation and transfer are carried out accordingly. 
     FIG. 41 is a diagram to show the conversion action of the fixed decimal point data and floating decimal point data. The input signal to the processor 44 is 32-bit fixed decimal point data per sampling period as mentioned above. The processor 44 calculates this input signal into floating decimal point data, and stores the result of calculation in the mantissa transmitting registers 61 and 62 of 16 bits for each and exponent transmitting registers 63 and 64 of 16 bits for each provided each for right and left channels. The thus stored data is processed arithmetically, in the processor 44, as 20-bit floating decimal point data per channel as indicated by reference codes 81 and 82. 
     The data stored in the mantissa transmitting registers 61 and 62, and exponent transmitting registers 63 and 64 are transferred from input terminals 73 and 74 of the processor 48 to mantissa receiving registers 67 and 68 and exponent receiving registers 69 and 70, through lines 65 and 66 from output terminals 71 and 72 provided separately for each one of registers 61 and 62; and 63 nd 64. The mantissa data transferred through the line 65 is shown in FIG. 40 (4), and the exponent data transferred through line 66 is shown in FIG. 40 (5). The processor 48, after arithmetically processing the transferred data as floating decimal point data of 20 bits per channel of right and left as shown by the reference codes 83 and 84, converts them into fixed decimal point data and supplied them to the digital/analog converter 62. 
     The mantissa data stored thus in the mantissa transmitting registers 61 and 62 is transferred to the mantissa receiving registers 67 and 68 through line 65 while the exponent data stored in the exponent transmitting registers 63 and 64 is transferred to the exponent receiving registers 69 and 70 through line 66, so that the mantissa data and exponent data may be transferred in parallel. Without using special converter circuitry such as bit number converting circuits 25 and 29 as mentioned in relation to the background technology, it is possible to process arithmetically or transfer by using clock signals common with the analog/digital converter 46 and others, so that the structure may be simplified. 
     Thus, according to the present invention, since the mantissa portion and exponent portion of the floating decimal point data are stored in the separate registers, it is possible to process arithmetically and transfer by synchronously controlling both registers by a common clock signal, and the structure may be simplified at the same time. 
     FIG. 42 is a block diagram showing a construction of another embodiment of the present invention, in which the data is transferred by the data transfer method of the invention between processors DSP3 and DSP4. 
     The processors DSP3 and DSP4 are similar in structure, and the structure of the processor DSP3 is explained below. 
     If the signal entering the processor DSP3 is fixed decimal point data, this fixed decimal point data is entered from line 7 as a serial signal. If the data entering the processor DSP3 is floating decimal point data, the exponent portion of the floating decimal point data is entered from line 7, and the exponent portion of the floating decimal point data is entered from line Pa as a parallel signal. The serial signal of line 7 is fed to the mantissa receiving register 11, and the parallel signal of line Pa is fed to the exponent receiving register 12. The data in the mantissa receiving register 11 is entered in the mantissa register 13a of the register 13, while the data in the exponent receiving register 12 is fed into the exponent register 13b of the register 13 similarly. 
     The data in the mantissa register 13a and exponent register 13b are supplied to an internal bus 16 by way of gates 14a and 14b, respectively. The data is supplied from the internal bus 16 to the memory circuit (not shown), etc. A processing circuit 15 arithmetically processes such data. 
     If the result of arithmetic processing in the processor DSP3 is fixed decimal point data, the fixed decimal point data as the result of arithmetic processing is entered form the internal bus 16 into the mantissa register 18a through gate 17a. This fixed decimal point data is fed to the mantissa transmitting register 19 of the mantissa register 18a. The data of this mantissa transmitting register 19 is transferred to the processor DSP4 as a serial signal through line 8. 
     If the result of arithmetic processing at the processor DSP3 is floating decimal point data, the mantissa portion and exponent portion of the floating decimal point data which is the result of a calculation are delivered to the mantissa register 18a and exponent register 18b of the register 18 respectively through gates 17a and 17b from internal bus 16. 
     The data of the mantissa register 18a is fed to the exponent transmitting register 19. The data in the exponent register 18b is supplied to the exponent transmitting register 20. 
     The mantissa portion of the floating decimal point data which is the result of arithmetic processing in the processor DSP3 is transferred from the mantissa transmitting register 19 to the processor DSP4 as a serial signal through line 8, and the exponent portion of the floating decimal point data is transferred to the processor DSP4 through line Pb as a parallel signal from the exponent transmitting register 20. 
     At the processor DSP4, the serial signal of line 8 is entered into the mantissa receiving register 21, and the parallel signal of line Pb is entered into the exponent receiving register 22. Afterwards, after arithmetic processing, as in the case of processor DSP3, the result of arithmetic processing is output to lines 9 and Pc from the mantissa transmitting register 29 and exponent transmitting register 30. 
     To the processors DSP3 and DSP4, a synchronous clock signal SYNC and a serial clock signal SCK for transferring the data synchronously are supplied. 
     FIGS. 43(1)-43(4) are waveform diagrams for explaining the data transfer operation between the processors DSP3, and DSP4, and the following explanation is made by reference to these diagrams. 
     The synchronous signal SYNC entered in the processor DSP3 is shown in FIG. 43 (1). From rise or fall of the synchronous signal SYNC, data transfer of one of the serial signals is started, and upon rise of the serial clock signal SCK shown in FIG. 43 (2), the serial signal of line 7 shown in FIG. 4 (3) is latched. 
     Upon next fall or rise of synchronous signal SYNC, one data transfer of serial signal is terminated, and a next data transfer is started. At this time, the data of serial signal expresses the fixed decimal point data when the processor DSP3 delivers fixed decimal point data, and represents the mantissa portion of the floating decimal point data when it delivers floating decimal point data. 
     When the processor DSP3 delivers floating decimal point data, the exponent portion of the floating decimal point data is output as a parallel signal shown in FIG. 43 (4) to the line Pb, and at the processor DSP4, this parallel signal is latched upon the rise and fall of the synchronous signal SYNC. 
     In this embodiment, thus, the transfer at the serial port for data input, output is effected similarly by same serial clock signal whether the data is fixed decimal point data or floating decimal point data. Therefore, in the processors DSP3, and SDP4, it is possible to distinguish the fixed decimal point data from floating decimal point data by detecting the presence or absence of the exponent portion by the software, so that the structure of the processor may be simplified. Besides, as compared with the parallel transfer of all these data transfers, for example, the number of conductors for input and output can be decreased, and the wiring may be simplified. Furthermore, if the data format differs between input and output, only one kind of frequency is enough for a serial clock signal, and the composition of the clock signal generator may be simplified. 
     In this embodiment, as the parallel port for input and output of the mantissa portion of the floating decimal point data, a general-purpose parallel port may be used, or when an exclusive parallel port is provided, this parallel port may be used as the input and output port of other data when inputting or outputting fixed decimal point data. 
     FIG. 44 is a further practical embodiment of the present invention, and corresponding parts to those mentioned in the foregoing embodiments are identified with same reference codes. 
     In this embodiment, data is transferred between an analog/digital converter AD2 and processor DSP3, between processors DSP3 and DSP4, and between processor DSP4 and a digital/analog converter DA2. 
     An analog signal, for example, an acoustic signal is entered from line 6 into the analog/digital converter AD2. From the analog/digital converter AD2, a digital signal of fixed decimal point data having a data length of, for example, 16 bits is delivered from line 7 into processor DSP3. Data transfer from the analog/digital converter AD2 to processor DSP3 is effected synchronously by the serial clock signal SCK and synchronous signal SYNC delivered from the clock signal generator CK2. 
     The fixed decimal point data entered in the processor DSP3 is arithmetically processed, and floating decimal point data possessing, for example, 16-bit mantissa portion and 3-bit exponent portion is delivered. As stated above, the mantissa portion of the floating decimal point data is given to the processor DSP4 through line 8, and the exponent portion of the floating decimal point data is given to the processor DSP4 through line Pb. In the data transfer of this case, too, same as in the data transfer from the analog/digital converter AD2 to processor DSP3, the data is transferred synchronously by the serial clock signal SCK from the clock signal generator CK2 and synchronous signal SYNC. 
     The floating decimal point data entered in the processor DSP4 is arithmetically processed, and is converted into fixed decimal point data. This fixed decimal point data is delivered to the digital/analog converter DA2 through line 9. In this data transfer also, data is transferred synchronously by the serial clock signal SCK from the clock signal generator CKS and synchronous signal SYNC. At the digital/analog converter DA2, the input fixed decimal point data is converted into an analog signal, and is led out to line 10. 
     When transferring the acoustic signal after analog/digital conversion as in this embodiment, the output from the analog/digital converter circuit and the input to the digital/analog converter circuit are usually fixed decimal point data, and the data transfer between processors is carried out by the floating decimal point data. When the data transfer method of the invention is employed in such case, if the data formal differs between the input and output at the processors DSP3 and DSP4, data can be transferred by the same serial clock signal, and the structure of the processor may be simplified, and all data can be transferred by only one kind of serial clock signal. Therefore, the wiring may be simplified, and complicated circuit composition such as digital phase-locked loop is not needed for the generation of clock signals. 
     As explained herein, in the data transfer method of the present invention, the transfer of fixed decimal point data in the same format as the mantissa portion of floating decimal point data, for example, may be similarly effected by a synchronous signal as for the floating decimal point data, by using the mantissa registers of the processor. 
     Therefore, both fixed decimal point data and floating decimal point data can be transferred in a simple structure. 
     FIG. 45 is a block diagram of another embodiment of the present invention. Analog sound signals of right and left channels are fed into the analog/digital converter AD2 from line 11, and the fixed decimal point data is fed to the processor DSP4 for the portion of two channels. This processor DSP4 arithmetically processes the sound signal which is the two-channel fixed decimal point data, and produces floating decimal data. The signal from the processor DSP4 is transmitted from the mantissa transmitting register A11 and exponent transmitting register B11 through lines 15 and 16, and is supplied to the mantissa receiving register A12 and exponent receiving register B12 of the other processor DSP5. 
     In the processor DSP5, various floating decimal point data processings are performed, and finally they are converted into a fixed decimal point format, and the sound signal data for four channels for four speakers 2 are stored in the mantissa transmitting register A13, and the fixed decimal point data which is the sound signal for a superwoofer 3 is stored in the exponent register B13. 
     The signal from the mantissa transmitting register A13 is stored in the register A14 of the digital/analog converter DA3 from line 12, and the sound signals for the portion of four channels are converted into analog sound signals as fixed decimal point data. To the low pass filter 4 provided thus for each channel, analog sound signals are fed, and the output from this low pass filter 4 is amplified by the amplifier circuit 5, and the speakers 2 are driven. 
     The sound signal for the superwoofer 3 from the exponent transmitting register B13 of the processor DSP5 is supplied from line 13 to a serial/parallel converter 14 to be converted into parallel bit signals, which are sent into digital/analog converter DA4 to be converted into an analog signal. The analog sound signal from this digital/analog converter DA4 is supplied to the amplifier circuit 7 through low pass filter 6, and the superwoofer 3 is driven. 
     FIG. 46 is a block diagram showing a composition relating to processors DSP4, DSP5, digital/analog converter DA3, and registers X1 to X7, A11 to A14, B11 to B13 of serial/parallel converter 14. The two-channel sound signal data which is the fixed decimal point data from the analog/digital converter AD2 is fed into the receiving register Xl in the processor DSP4 through line 41. 
     The data thus input is two-channel fixed decimal point data, and is fed into store regions N1 and N2 of receiving register X1, while the remaining store regions N3 and N4, and store regions H1 to H4 of receiving register X2 are empty. When the data input is over, the empty store regions N3 and N4; and H1 to H4 are handled as 0, and the contents in the store regions N1 to N4 of receiving register X1 are stored in the store regions R1 to R4 of the register X3, while the contents in the store regions H1 to H4 of receiving register X2 are stored in the store regions R1 to R4 of the register X3. At this time, the fixed decimal point data is converted into the floating decimal point data at the exponent portion 0. 
     A processing circuit 29 reads out these data through gates 42 and 43, and data bus 17, and various floating decimal point arithmetic processings such as tone control are effected on the two-channel sound signal (floating decimal point data) by using the data of a memory (not shown), and four-channel floating decimal point data is created, which is stored in the register X4 through gates 44, 45. 
     The register X4 can store a total of four sets of floating decimal point data, and the mantissa portion of the floating decimal point data is indicated by reference codes L1 to L4, and the exponent portion is indicated by M1 to M4. For example, the first floating decimal point data is composed of mantissa portion L1 and exponent portion M1, and these floating decimal point data M1 and L1; M2 and L2; M3 and L3; and M4 and L4 are sound signals for four channels. The mantissa portions L1 to L4 stored in the register X4 are respectively stored in the store regions C1 to C4 of the mantissa transmitting register All. The exponent portions M1 to M4 are respectively stored in the store regions D1 to D4 by the exponent transmitting register B11. Each one of mantissa portions L1 to L4 is composed of 16 bits, and each one of exponent portions M1 to M4 is 4-bit data. 
     The contents in the store regions C1 to C4 of the mantissa transmitting register A11 are transferred to the store regions E1 to E4 respectively of the mantissa receiving register A12 of the processor DSP5 through line 15. Likewise, the contents in the store regions D1 to D4 of the exponent transmitting register B11 are transferred to store regions F1 to F4 of the exponent receiving register B12 through line 16, respectively. The store contents in the mantissa receiving register A12 and exponent receiving register B12 are fed into the register X5. 
     The register X5 possesses the regions for receiving four sets of floating decimal point data, and the mantissa portions P1 to P4 and exponent portions Q1 to Q4 of each one of floating decimal point data are stored in the unit of floating decimal point data. The processing circuit 24 of the processor DSP5 reads out the data, when the input of the data is over, from the register X5 through the gates 45, 46, and the floating decimal point arithmetic processings are performed again, and the results are added to the four-channel sound signal data, and the sound signal data for a one-channel superwoofer 3 is obtained. Such an arithmetic processing is performed by using the data stored in the memory (not shown) provided in the processor DSP5, and according the one-channel floating decimal point data (the sound signal for the superwoofer 3 in this embodiment) is obtained additionally. 
     The data is stored in the register X6 by way of data bus 23 and gates 47 and 48. The register X6 possesses the region for receiving four sets of floating decimal point data, and the mantissa portions T1 to T4 and exponent portions U1 to U4 of the floating decimal point data, the mantissa portions T1 to T4 and exponent portions U1 to U4 of the floating decimal point data are stored in the unit of floating decimal point data. 
     Here, since the digital/analog converters DA3 and DA4 handle the fixed decimal point data, finally five sets of floating decimal point data, that is, four sets of floating decimal point data expressing sound signals for four channels, and the floating decimal point data expressing the sound signal for the superwoofer 3 are converted into fixed decimal point data, and the data for four channels are stored in the register for mantissa A13, and the data for superwoofer 3 for one channel is stored in the register for exponent B13, and are transferred to the receiving register A14 of the digital/analog converter DA3, and the receiving register X7 of the serial/parallel converter 14 which is the interface circuit for the digital/analog converter DA4. 
     FIGS. 47(1)-47(4) are waveform diagrams for explaining the operation of the constitution shown in FIG. 46. From the clock signal generator 25 to line 26, a control signal SYNC shown in FIG. 47 (1) is output, and a control signal SCLK shown in FIG. 47 (2) is output to the line 27. In one period from the fall of the control signal SYNC to the next trailing edge, the bit-sequential data from the mantissa transmitting register A11 is sequentially transferred to the line 15 as shown in FIG. 47 (3). In the period when the control signal SYNC is at low level, the bit-sequential data from the exponent transmitting register B11 is led out to the line 16 as shown in FIG. 47 (4), and is transferred. In this way, the mantissa transmitting register A11 and exponent transmitting register B11 deliver outputs independently, and are controlled in synchronism by the control signals SYNC and SCLK which are common clock signals. This holds true with the mantissa receiving register A12 and exponent receiving register B12, and also with the registers A13, A14, B13, and X7. 
     The exponent portion has 4 bits in the above embodiment, and 16-bit sound signal is transferred for the superwoofer 3 from the processor DSP5, but as other embodiment of the invention it may be also possible to process the sound signal in 8 bits, for example, for the superwoofer 3 by using the exponent portion. 
     FIG. 48 is a block diagram of a different embodiment of the present invention, which is similar to the foregoing embodiment, and corresponding parts are identified with same reference codes. What is of not in this embodiment is that the floating decimal point data is bit-sequentially transferred by single data lines 30 and 31. In this embodiment, the data is transferred in the common lines 30 and 31 by the mantissa portion and exponent portion of the floating decimal point data, but by controlling this transfer timing, the mantissa portion and exponent portion are distinguished at the transmitting and receiving sides, and are separately stored in the registers, so that the sound signals for four channels and the sound signal for the superwoofer 3 may be arithmetically processed, and used. Besides, by using the 4-bit sound signal of each channel from the exponent transmitting register B13 by two each, it is also possible to process the sound signal for the speaker of another channel indicated by reference code 3a, aside from the superwoofer 3 mentioned above. The constituent elements relating to the speaker 3a are indicated by broken lines, and the constitution for the superwoofer 3 is indicated by the subscript a. 
     The invention may be embodied not only in processing of sound signal, but also widely in other technical fields. 
     Thus, according to this invention, eliminating the in the circuit composition, the cost may be reduced in the processing apparatus. 
     FIG. 49 is a block diagram showing the configuration near processor DSP4 in an embodiment of the present invention. The processor DSP4 is composed of mantissa receiving register A10 and mantissa transmitting register A11 which are mantissa registers, and exponent receiving register B10 and exponent transmitting register B11 which are exponent registers, and is designed to transfer data with a similarly composed processor DSP5. 
     For example, an analog signal such as acoustic signal is fed from line 11 into analog/digital converter AD2 to be converted into a digital signal. This digital signal is usually fixed decimal point data, and possesses a data length of, for example, 16 bits. This fixed decimal point data is delivered from the transmitting register A9 of the analog/digital converter AD2 into the mantissa receiving register A10 of the processor DSP4. 
     To the exponent receiving register B10 of the processor DSP4, a signal, for example, from a potentiometer 1 for detecting fluctuations in external voltage is entered after being converted into a digital signal of low bits, such as 3 bits, in the analog/digital converter AD1. The data in the mantissa receiving register A10 and exponent receiving register B10 are given to the internal bus D1 by way of mantissa register C1a and exponent register C1b of the internal register C1. 
     At the processor DSP4, according to the data from the exponent register C1b, the data from the mantissa register C1a is arithmetically processed, and the floating decimal point data is obtained as the result of this calculation. The mantissa portion and exponent portion of this floating decimal point data are delivered to the mantissa transmitting register A11 and exponent transmitting register B11 through the mantissa register C1a and exponent register C1b of the internal register C1. 
     The data in the mantissa transmitting register A11 and exponent transmitting register B11 of the processor DSP4 are transferred to the mantissa receiving register A12 and exponent receiving register B12 of the processor DSP5 through lines 15 and 16 respectively, and the floating decimal point data is thus transferred between the processors DSP4 and DSP5. 
     At the processor DSP5, the floating decimal point data in the mantissa receiving register A12 and exponent receiving decimal register B12 are sent into the internal bus D2 through the mantissa register C2a and exponent register C2b of the internal register C2 to be processed arithmetically. If this result of calculation is, for example, fixed decimal point data, the fixed decimal point data from the internal bus D2 is fed to the mantissa transmitting register A13 through the mantissa register C2a of the internal register C2. The output from the mantissa transmitting register A13 is supplied to the digital/analog converter or the like through the line 12. 
     At this time, if the result of the calculation obtained by a different processing from the floating decimal point data of the mantissa receiving register A12 and exponent receiving register B12 is entered in the exponent transmitting register B13, it may be designed to deliver the signal from the line 13 through the exponent transmitting register B13. 
     In this embodiment, since it is designed to process arithmetically in the processor DSP4 according to the data entered in the exponent receiving register B12 through the analog/digital converter AD1 from the potentiometer 1, the configuration shown in FIG. 49 may be applied, for example, in the linear control such as volume control and open loop adaptive control. 
     FIG. 50 is a diagram to explain the operation when a function of an electronic volume control is added to the processor DSP4. Fixed decimal point data representing an acoustic signal is output from the analog/digital converter AD2 to the line 14, while the signal from the potentiometer 1 is converted into a digital signal by the analog/digital converter AD1 and is output to the line 10. 
     In the processor DSP4, as shown in FIG. 50, the data from the line 14 is digitally amplified at an amplification factor according to the data from the line 10, and is delivered. In this way, the acoustic signal can be controlled to a desired volume level by the potentiometer 1. 
     FIG. 51 is a block diagram showing a different embodiment of the present invention, and the parts corresponding to those in the foregoing embodiment are identified with same reference codes. 
     In this embodiment, the signal entered in the exponent receiving register B10 of the processor DSP4 is a control command of the processor DSP4. The signal to represent the control command of the processor DSP4 is entered in a flag generator 2, and a flat to show a control command is entered in the exponent receiving register B10 through line 10 from the flag generator circuit 2. 
     The exponent portion of the floating decimal point data is generally of low bits, but its data length is sufficient as the flag of command for controlling the processor DSP4 from outside, and it may be used when changing over the operation program of the processor DSP4 by force, for example. 
     In this way, the processor DSP4, when entering the fixed decimal point data of, for example, analog/digital converter, enters the fluctuations of external power source or control command by effectively utilizing, without any waste, the input terminal of the exponent portion of floating decimal point data or exponent receiving register B10. Therefore, the processor can process the data at higher speed, and the application range of the processor is expanded. 
     In this embodiment, as the port for input and output of the processor DSP4, the serial port and general-purpose parallel port usually possessed by the processor may be utilized as for the mantissa portion of the floating decimal point data, fixed decimal point data, and exponent portion of floating decimal point data. 
     According to the present invention, as clear from the description herein, when fixed decimal point data in the same format as the mantissa portion of floating decimal point data is entered in, for example, the processor, the fixed decimal point data is stored in the mantissa register, and other data may be entered and stored in the exponent register. 
     Therefore, waste in the construction of the processor may be eliminated, and more advanced data processing making full use of the functions of the processor may be realized. 
     FIG. 52 is a block diagram showing an acoustic signal processor 21 in another embodiment of the present invention. For example, an analog acoustic signal from a radio receiver is fed to an analog/digital converter 23 from an input terminal 22 to be converted into a digital signal, and is fed to a processor 24 realized by large scale integration. 
     The processor 24 arithmetically processes the input signal by addition, multiplication or the like, or by a delay operation, and processes the acoustic signal for tone control or echo. The output of the processor 24 is fed to a processor 25 for other arithmetic processing, and is supplied to digital/analog converters 26 and 27 to be converted into analog signal, which are fed to a power amplifier circuit or the like from output terminals 28 and 29. 
     The output of the analog/digital converter 23 is, as shown in FIG. 53 (i), composed of a total of 32 bits of fixed decimal point data, of 16 bits each of right and left channels per sampling period. The processors 24 and 25, analog/digital converter 23, and digital/analog converters 26 and 27 operate arithmetically on basis of a clock signal SCLK from clock generator circuit 30 shown in FIG. 53 (2), and the synchronous signal SYNC shown in FIG. 53 (3). 
     FIG. 54 is a block diagram showing an internal structure of processors 24 and 25. The processors 24 and 25 are identical in structure, and for the sake of simplicity, in FIG. 54, only the transmission system is shown as the processor 24 and only the reception system is shown as the processor 25. The input signal to the processors 24 is, as stated above, 32-bit fixed decimal point data per sampling period. 
     Here, in order to inhibit the deterioration of the dynamic range of S/N ratio due to overflow or underflow at the time of arithmetic processing, when using the processors 24 and 25 for use in transfer of floating decimal point data, the processor 24 converts this input signal into floating decimal point data, and stores it. The thus stored data is, in the processor 24, arithmetically processed as floating decimal point data of 20 bits each of right and left channels as indicated by reference codes 35 and 36. The data in 16-bit mantissa regions B1 and B3 are stored in 16-bit mantissa transmitting registers 31 and 32, and the data in 4-bit exponent regions B2 and B4 are stored in 4-bit regions A1 and A2 of 16-bit exponent transmitting registers 33 and 34. 
     The data stored in the mantissa transmitting registers 31 and 32 and exponent transmitting registers 33 and 34 are transferred from the output terminals 51 and 52 individually provided for registers 31, 32, 33, and 34, to 4-bit regions C1 and C2 of 16-bit mantissa regions 41 and 42 and 16-bit exponent receiving registers 43 and 44 from input terminals 61 and 62 of the processor 25 through lines 71 and 72. 
     At this time, the mantissa data transferred through line 71 is indicated in FIG. 53 (4), and the exponent data transferred through line 72 is indicated in FIG. 53 (5). At the processor 25, the transferred data is arithmetically processed as 20-bit floating decimal point data each of right and left channels composed of 16-bit mantissa portion and 4-bit exponent portion as shown by reference codes 45 and 46, and is converted into fixed decimal point data of two channels each of 16 bits of each channel (total 4 channels), and is supplied to the digital/analog converters 26 and 27. 
     On the other hand, in order to transfer multiple data simultaneously between processors 24 and 25, if slightly lowering the precision, when the processors 24 and 25 are used for transfer of fixed decimal point data, the processors 24 converts the input signal of fixed decimal point data into floating decimal point data, and processes it arithmetically, and converts it into fixed decimal point data, and the result of this operation is stored in 16-bit mantissa transmitting registers 31 and 32 provided for right and left channels. Meanwhile, the exponent transmitting registers 33 and 34 store the fixed decimal point data aside from 16 bits of right and left channels indicated by reference codes 37 and 38. In this case, too, the operation is same as in the above case in that the arithmetic processing is carried out after converting it into floating decimal point data of 20 bits each of right and left channels in the processor 24. 
     The data stored in the mantissa transmitting registers 31 and 32 and exponent transmitting registers 33 and 34 are transferred to the mantissa receiving registers 41 and 42 and exponent receiving registers 43 and 44 through lines 71 and 72, as in the above case. At this time, the fixed decimal point data transferred through the line 71 is indicated in FIG. 53 (6), and the other fixed decimal point data transferred through the line 72 is indicated in FIG. 53 (7). They are both 16-bit fixed decimal data per channel (32 bits per sampling period). 
     The processor 25 arithmetically processes the transferred fixed decimal point data as 20-bit floating decimal data each of right and left channels, and processes in the same manner as the processor 24 to convert into fixed decimal point data of two channels each of right and left of 16 bits per channel (total 4 channels), and sends into digital/analog converters 26 and 27 in every data per sampling period. 
     In this way, since the exponent registers 33 and 34, and 43, 44 are of the same length (16 bits in this embodiment) as the mantissa registers 31 and 32, and 41 and 43, when transferring fixed decimal point data between processors 24 and 25, it is possible to transfer simultaneously the other 16-bit fixed decimal point data of right and left channels by using the exponent registers 33 and 34, and 43 and 44, so that the transfer capacity is twice as much as in the prior art. Moreover, between the processor 25 and the digital/analog converters 26 and 27, since fixed decimal point data of two channels each of 16 bits per channel can be transferred simultaneously, it is extremely effectively when applying the acoustic signal processor 21 in a processor for a four-channel stereo audio appliance. 
     In the present invention, therefore, since the exponent registers are the same bit length as the mantissa registers, it may be effectively used in processing of floating decimal point data and fixed decimal point data, so that multiple data can be transferred. 
     FIG. 55 is a block diagram showing an acoustic signal processor 21 in an embodiment of the present invention. For example, an analog acoustic signal from a radio receiver is fed to an analog/digital converter 23 from an input terminal 22, and is converted into a digital signal, which is fed to a processor 24 realized by large scale integration or the like. 
     The processor 24 processes this input signal by addition, multiplication or other arithmetic operation or delay operation, and processes the acoustic signal such as tone control and surround. The output of the processor 24 is supplied to a processor 25 for other arithmetic processing, and is fed to a digital/analog converter 26 to be converted into an analog signal, which is fed to a power amplifier or the like through output terminal 27. 
     The output of analog/digital converter 23 is composed of a total of 32 bits of fixed decimal point data of 16 bits each of right and left channels per sampling period as shown in FIG. 56 (1). The processors 24 and 25, analog/digital converter 23, and digital/analog converter 26 process arithmetically on the basis of the clock signal SCLK from clock generator 28 shown in FIG. 56 (2) and the synchronous signal SYNC shown in FIG. 56 (3). 
     The processors 24 and 25, in order to inhibit the deterioration of the dynamic range or the S/N ratio due to overflow or underflow at the time of processing, process arithmetically and transfer the data as floating decimal point data. Besides, the mantissa portion of the floating decimal point data handled in the processors 24 and 25 is of a longer bit length (18 bits in this embodiment) than the bit length (16 bits) of the fixed decimal point data handled outside in order to reduce operational errors and enhance the precision. 
     FIG. 57 is a block diagram showing an internal structure of processors 24 and 25. The processors 24 and 25 are identical in structure, and for the sake of simplicity, in FIG. 57, only the transmission system is shown in the processor 24 and only the reception system is shown in the processor 25. The input signal to the processor 24 is 32-bit fixed decimal point data per sampling period as mentioned above. 
     The processor 24 receives this input signal by a 16-bit mantissa receiving register (not shown) each of right and left channels. At this time, the exponent receiving register (not shown) composed of 2-bit mantissa region and 6-bit exponent region is not provided with data and is empty. When the input into the mantissa receiving register is over, the empty register is handled as 0, and the 16-bit fixed decimal point data each of right and left channels from the analog/digital converter 23 is converted into 24-bit floating decimal point data each of right and left channels composed of 18-bit mantissa portion and 6-bit exponent portion, and is processed arithmetically. The configuration of the reception system of the processor 24 is same as that in the processor 24 is same as that in the processor 25, of which details are described below. 
     The arithmetically processed floating decimal point data is stored in buffer registers 35 and 36 for transfer of 24 bits each for right and left channels from data bus 39 through gates 37 and 38. At this time, the 18-bit mantissa data of each channel is stored in regions A1, C1, and D1, and regions A2, C2, and D2, while the 6-bit exponent data is stored in region B1 and region B2. Of the 18-bit mantissa data, the data of upper 16 bits composed of 1-bit sign bit expressing the polarity stored in regions A1 and A2 and 15-bit data stored in regions C1 and C2 is stored in the shift registers 31 and 32 for mantissa transmission of 16 bits each. Besides, the 6-bit exponent data stored in regions B1 and B2 and the lower 2-bit remaining mantissa data stored in regions D1 and D2 are respectively stored in shift registers 33 and 34 for exponent transmission of 8 bits each. 
     The data stored in the mantissa transmitting registers 31 and 32, and exponent transmitting registers 33 and 34 are transferred through lines 71 and 72 from the output terminals 51 and 52 individually provided for registers 3 and 32, 33 and 34 on the basis of the common clock signal SCLK and synchronous signal SYNC, to 16-bit exponent receiving registers 41 and 42, and 8-bit exponent receiving registers 43 and 44, from input terminals 61 and 62 of the processor 25. Incidentally, the data is stored in the buffer registers 35 and 36 at arbitrary timing, and data transfer from the buffer registers 35 and 3 to the mantissa transmitting registers 31 and 32 and to exponent transmitting registers 33 and 34 is effected, for example, after every termination of data transfer from the mantissa transmitting registers 31 and 32. The mantissa data transferred through the line 71 is indicated in FIG. 56 (4), and the exponent data and remaining mantissa data transferred through the line 72 is shown in FIG. 56 (5). The contents of the registers 41, 42, 43, and 44 are stored in the buffer registers 45 and 46 for transfer upon every termination of data transfer to the mantissa receiving registers 41 and 42 and exponent receiving registers 43 and 44. At this time, of the data transferred to the mantissa receiving registers 41 and 42, sign bits of 1 bit each are stored in regions A3 and A4 of buffer registers 45 and 46, and the mantissa data of the remaining 15 bits each are stored in regions C3 and C4 of the buffer regions 45 and 46. Of the data transferred to the exponent receiving registers 43 and 44, the exponent data of 6 bits each are stored in regions B3 and B4 of buffer registers 45 and 46, and the remaining mantissa data of 2 bits each are stored in regions D3 and D4 of buffer registers 45 and 46. The floating decimal point data of 24 bits each of right and left channels stored in the buffer registers 45 and 46 are read out through gates 47 and 48 at arbitrary timing, and are transferred through the data bus 49, and are processed arithmetically by an arithmetic processing circuit (not shown). 
     The floating decimal point data of 24 bits of each channel arithmetically processed are converted into data expressed only by the mantissa portion of 18 bits while the exponent portion is all 0, that is, fixed decimal point data. In the 18-bit mantissa data, the upper 16 bits are stored in the mantissa transmitting register (not shown) as mentioned above, and the 6-bit exponent data of all 0 and the remaining mantissa data of lower 2 bits are stored in the exponent transmitting register (not shown), and the 16-bit mantissa data stored in the mantissa data stored in the mantissa transmitting register is transferred to the digital/analog converter 26 in the lower stage as 16-bit fixed decimal point data according to the clock signal SCLK and synchronous signal SYNC. In this way, part of mantissa portion (in this embodiment, data of upper 16 bits each) in the floating decimal data is stored in the mantissa registers 31 and 32 and 41 and 42, whereas the exponent portion (data of 6 bits each in this embodiment) and the remaining portion of mantissa (lower 2 bits) are stored in the exponent registers 33 and 34, and 43 and 44, and terminals 51 and 52, and 61 and 42 are provided in order to enter and deliver the contents in the mantissa registers 31 and 32, and 41 and 42, and the contents in the exponent registers 33 and 34, and 43 and 44 individually, so that it is not necessary to use a special converting circuit if the bit number of the mantissa portion in the floating decimal point data is longer than the bit length of the fixed decimal point data handled outside, thereby making it possible to process the data arithmetically and transfer it on the basis of a common clock signal (in this embodiment, 32 pulse signals per sampling period). In the data transfer between processors 24 and 25, too, the floating decimal point data may be directly transferred in the same format, and if the processor is divided into a plurality depending on the content or quantity of the arithmetic processing, the same processing precision as in a signal processor is obtained. 
     As explained in details herein, according to the present invention, if the bit number of the mantissa in the floating decimal point data for arithmetic processing is longer than the bit length of the fixed decimal point data handled outside, a special converting circuit is not needed, and it is possible to process arithmetically and transfer on a basis of a common clock signal, and the precision does not deteriorate. 
     FIG. 58 is a block diagram showing sound signal processor 21 in another embodiment of the present invention. An analog sound signal, for example, from a radio receiver entered from an input terminal 22 is converted into a digital signal in an analog/digital converter 23, and is supplied into a processor 24 realized by large scale integration or the like. At the processor 24, the input digital sound signal is processed arithmetically or by delay for the purpose of tone control or the like, and the output is fed to another processor 25. At this processor 25, a different arithmetic processing is carried out, and the thus processed digital sound signal is converted into an analog signal in a digital/analog converter 26, whose output is fed to a power amplifier or the like connected to an output terminal 27. 
     In thus composed sound signal processor 21, if the output fed to the processor 24 from the analog/digital converter 23 and the output fed to the digital/analog converter 26 from the processor 25 are stereo signals, supposing the right and left channels to have 16 bits each, they are fixed decimal point data of 32 bits in total per sampling period. By contrast, in the processors 24 and 25, in order to enhance the dynamic range and S/N ratio, the sound signal is composed of 16-bit mantissa portion and 4-bit exponent portion for each of the left and right channels, so that the sound signal is handled as floating decimal point data of 40 bits in total per sampling period in arithmetic processing and data transfer. 
     The processor 24, in order to store the input data, comprises a 32-bit mantissa receiving register A11 composed of 16-bit left channel cell A11a and 16-bit right channel cell A11b, and an 8-bit exponent receiving register A12 composed of 4-bit left channel cell A12a and 4-bit right channel cell A12b, in which the received data is given to a common contact 31 of a switch S11, and is selectively written into the mantissa receiving register All or exponent receiving register A12 respectively connected to the individual contacts 32 and 33. The processor 24 also comprises a 32-bit mantissa transmitting register B11 composed of 16-bit left channel cell B11a and 16-bit right channel cell B11b, and an 8-bit exponent transmitting register B12 composed of 4-bit left channel cell B12a and 4-bit right channel cell B12b, in which the data from the mantissa transmitting register B11 or exponent transmitting register B12 is applied to the individual contacts 34, 35 of the switch S12, and is read out selectively from the common contact 36. The switching format of the switch S11 and switch S12 is controlled by a control circuit 38. 
     The processor 25 is composed same as the processor 24, comprising a mantissa receiving register A21 composed of 16-bit left channel cell A21a and 16-bit right channel cell A21b, exponent receiving register A22 composed of 4-bit left channel cell A22a and 4-bit right channel cell A22b, manitssa transmitting register B21 composed of 16-bit left channel cell B21a and 16-bit right channel cell B21b, exponent transmitting register B22 composed of 4-bit left cell B22a and 4-bit right cell B22b, switches S21, S22, and control circuit 39. The control circuits 38 and 39 are coupled together by a line 40. The common contact 41 of the switch S21 is connected to the common contact 36 of the switch S12 through line 37, while one individual contact 42 is connected to the mantissa receiving register A21 and the other individual contact 43 is connected to the exponent receiving register A22. One individual contact 44 of tee switch S22 is connected to the mantissa transmitting register B12 and the other individual contact 45 is connected to the exponent transmitting register B22, while the common contact 46 is connected to the digital/analog converter 26. In FIG. 58, numerals 16, 4 shown in each register denote the number of bits in the store region of each register. 
     In this embodiment, at the processor 24 in the previous stage, the common contact 31 of the switch S11 keeps conduction with the individual contact 32, while at the processor 25 in the later stage, the common contact 46 of the switch S22 keeps conduction with the individual contact 44. 
     Therefore, the 32-bit fixed decimal point data from the analog/digital converter 23 is stored in the left and right channel cells A11a, A11b of the mantissa receiving register A11 of the processor 24, and is converted into 4-bit floating decimal point data, and is stored in the 4-bit register C11 composed of 20-bit left channel cell C11a and 20-bit right channel cell C11b. The data in the register C11 is arithmetically processed, and the data in the left channel cell C11a is stored in the left channel cell B11a of the mantissa transmitting register B11 and the left channel cell B12a of the exponent transmitting register B12, while the data in the right channel cell C11b of the register C11 is stored in the right channel cell B11b of the mantissa transmitting register B11 and right channel cell B12b of exponent transmitting register B12. While the switch S12 is conducting with the individual contact 34, the switch S21 is conducting with the individual contact 42, and while the switch S12 is conducting with the individual contact 35, the switch S21 is conducting with the individual contact 43. In this way, since the switching format of the switches S12 and S21 is controlled in cooperation, the contents in the left and right channel cells B11a and B11b of the mantissa transmitting register B11 are respectively transferred to the left and right channel cells A21a and A2Ib of the mantissa receiving register A21, while the contents in the left and right channel cells B12a and B12b of the exponent transmitting register B12 are respectively transferred to the left and right channel cells A22a and A22b of the exponent receiving register A22. 
     In the processor 25, the left channel data received by the left channel cell A21a of the mantissa receiving register A21 and the left channel cell A22a of the exponent receiving register A22 is stored in the 20-bit left channel cell C21a of the register C21; while the right channel data received by the right channel cell A21b of the mantissa receiving register A21 and the right channel cell A22b of the exponent receiving register A22 is stored in the 20-bit data is arithmetically processed, and is converted into 32-bit fixed decimal point data, and is supplied from the left and right channel cells B21a and B21b of the mantissa transmitting register B21 into the digital/analog converter 26. 
     By controlling the switching format of the switches S11, S12, S21, and S22 in this manner, the processors 24 and 25 can share a same integrated circuit, and moreover this integrated circuit may be realized in a relatively simple circuit configuration, so that the cost for components may be saved. 
     According to the present invention, hence, since the mantissa register and exponent register can be selectively connected to terminals for transmission or terminals for reception, by the switching means controlled in switching format by control means, if the formats of the data transmitted are different, the circuit configuration can be commonly shared for transmission and reception, and therefore it is extremely advantageous for realizing the processor by integrated circuits in particular.