fig1 is a schematic diagram illustrating the structure and operation of a general semiconductor memory circuit . in this figure , ml is the left memory cell group and mr is the right memory cell group , thus the word decoders are provided between the groups for corresponding rows . however , in this figure , only the word decoder wdk of the kth row is indicated . the word decoder wdk drives the full length of the word line wlk . when considering the left memory cell group ml , the n memory cells cl1 to cln are connected along the word line wlk and each of the memory cells comprises a pair of fets ( 1 , 2 ) which operate in the complementary mode and a pair of transfer fets ( 7 , 8 ). to each pair of fets ( 1 , 2 ), the bit lines ( bl1 , bl1b ) to ( bln , blnb ) are connected via transfer fets ( 7 , 8 ). the bit lines ( bl1 , bl1b ) to ( bln , blnb ) respectively output the complementary logical bit data of the respective memory cells . the bit data is applied to a pair of fets ( 3 , 4 ) connected to each of the column decoders cdl1 to cdln , then to the sense circuit 21 via the wired ored fets ( 3 , 4 ) associated with the column decoders cdl1 to cdln , and finally output as the memory output m out via the output circuit 22 . the fets ( 5 , 6 ) in each of the bit lines bl1b , bl1 . . . blnb , bln are load fets . the abovementioned structure is applied analogously to the right memory cell group mr , where cdr1 to cdrn are column decoders , br1 , br1b . . . brn , brnb are bit lines , cr1 to crn are memory cells . if the address is specified for the memory cell cl1 ( memory cell connected to the first bit lines ( bl1 , bl1b ) within the left memory cell group ml ), the word decorder wdk associated with the memory cell cl1 is specified by the word address adwk . the word address adwk consists of address bits a 0 ( or a 0 ), a 1 ( or a 1 ), a 2 ( or a 2 ), a 3 ( or a 3 ) and a 4 ( or a 4 ) when the number of memory cells in the column direction is 32 . when the word decoder wdk is specified by the word address adwk , all of the fets ( 9 , 10 , 11 , 12 and 13 ) comprising the word decoder wdk are turned off and therefore word line wlk becomes a high , &# 34 ; h &# 34 ; level so that the transfer fets ( 7 , 8 ) of the corresponding memory cells are turned on . thereby , the bit current il1 to iln and ir1 to irn flows through each fet storing the logic low data &# 34 ; l &# 34 ; among pair of fets ( 1 , 2 ) of the memory cells cl1 to cln and cr1 to crn associated with the word line wlk , from the power supply v cc to the power supply v ss . then , the column decoder cdl1 corresponding to the relevant memory cell cl1 and is designated by the column address adcl1 , and the data stored in the memory cell cl1 is output through the sense circuit 21 and output circuit 22 via the bit lines ( bl1 , bl1b ). the column address adcl , comprises address bits a 5 ( or a 5 ), a 6 ( or a 6 ), a 7 ( or a 7 ), a 8 ( or a 8 ) and a 9 ( or a 9 ) when the number of memory cells in the word direction is 32 . when focusing on the bit current , even while the address is specified only for the memory cell cl1 , unwanted and useless bit current also flows into all memory cells other than said memory cell . the total excess bit current becomes very large as high as indicated by the following equation . ## equ1 ## this fact means that the power consumption becomes high and high speed operation is considerably restricted because all memory cells must be deiven at the same time . therefore , in the present invention , additional circuits are connected to each word decoder to reduce the total amount of bit current by a half . fig2 shows an embodiment of the present invention . in this figure , the left memory cell group ( ml ) drive gate 31l and the right memory cell group ( mr ) drive 31r are provided in the left and right sides of each word decoder . also only one of the right and left memory cell group drive gates 31r and 31l is conductive at a time . the gates 31r and 31l each receive the lowest ( last ) column address bit a 9 and its complementary bit a 9 , for example , which indicates whether the memory cell to be accessed is located in the right or left memory cell groups ( mr or ml ). according to the above example , since the memory cell cl1 of the left memory cell group ml is designated , the address bit a 9 is a logic &# 34 ; 1 &# 34 ; i . e . &# 34 ; h &# 34 ; level . thus , the left memory cell group drive gate 31l is turned on and simultaneously the right memory cell group drive gate 31r is turned off . thus the right side of the word line wlk is not driven and the current indicated by ## equ2 ## of the above equation becomes zero . on the contrary , if a memory cell in the right memory cell group mr is accessed , the address bit a 9 is logic &# 34 ; 0 &# 34 ; i . e . &# 34 ; l &# 34 ; level and the right memory cell group drive gate 31r is turned on and simultaneously the left memory cell group drive gate 31l is turned off . therefore , the left part of the word line wlk is not driven and thus the current indicated by ## equ3 ## of the above equation , becomes zero . thus , the power consumption specified by the total bit current of the above equation becomes almost one - half of the power consumption for the conventional device . the right and left memory cell group drive gates 31r and 31l respectively comprise transistors ( 32 , 33 ) and transistors ( 34 , 35 ). the transistors 32 and the transistor 34 are inserted in series with the word line but the transistor 34 and the transistor 35 are connected in parallel between the word line and the power supply v ss . in principle , the desired gate function can be obtained with only the transistor 32 and the transistor 34 , but it is desirable to hold the corresponding right or left word line forcibly at the specified potential ( v ss ) by means of the transistor 33 or 35 which turns on simultaneously with the transistors 34 or 32 when they turn on . thus preventing the right or left word line from floating , resulting in errorneous operation when the transistor 32 or 34 turns off . namely , the transistors 32 and 33 turn on or off complementarily and the transistors 34 and 35 also turn on or off complementarily . in addition , the transistors 32 and 34 must turn on or off alternatively and therefore they require the signals ; a 9 and a 9 as the signals . according to the above example , in case the memory cell cl1 is specified , the transistor 34 turns on because a 9 =&# 34 ; h &# 34 ; and the transistor 35 turns off because a 9 =&# 34 ; l &# 34 ;. on the other hand , the transistor 32 turns off because a 9 =&# 34 ; l &# 34 ; and the transistor 33 turns on because a 9 =&# 34 ; h &# 34 ;. in this case , the memory cells in the right side can be put into the not - selected condition without being placed in the floating mode . fig3 shows examples of an arrangement pattern of word decoders and memory cell groups in which the present invention can be applied . fig3 ( b ) shows the arrangement pattern in which two word decorders ( wd a , wd b ) are provided between the first right memory cell group mr a and the first left memory cell group ml a , and the second right memory cell group mr b and the second left memory cell group ml b , respectively . as explained above , the present invention realizes a semiconductor memory circuit which has reduced the power consumption to almost 1 / 2 that of conventional devices , and which is also suitable for a high speed operation . it will be obvious that the present invention is not restricted to the above - mentioned embodiment , and that many variations are possible for those skilled in the art without departing from the scope of the present invention .