At initialization of conventional multi-board systems, each circuit board attempts to locate its memory, interrupt addresses, registers, bus grants, etc., at the same address. A number of jumpers or strapping devices are used to configure or memory map the memory, interrupt addresses and registers so that they do not overlap. However, most conventional systems require a qualified individual who can reconfigure the circuit boards to place the jumpers or strapping devices in the proper position and/or location so that each circuit board is configured in a particular order.
When plugging a mezzanine (or daughter) circuit board onto either side of a master circuit board (or a mother board), enable signals are sent in a daisy chain fashion from one circuit board to another circuit board. Therefore, if a mezzanine board is placed on top of the master board, the enable signals are passed from the master board to the mezzanine board. If the mezzanine board is placed on the other side of the master board, the enable signals are passed in that direction from the master board to the mezzanine board. However, a skilled person is needed who knows how to manually change the jumpers or strapping devices on both the master and mezzanine boards so that the enable signals travel in the proper direction.
If mezzanine boards are to be placed on both sides of the master board, the jumpers or strapping devices will have to be changed by a skilled person. In other words, each time the master and mezzanine boards are rearranged, jumpers or strapping devices are required so that the entire system initializes and configures correctly and functions properly. Thus, there is a significant need for a multi-board system which eliminates the intervention of a skilled person for changing jumpers or strapping devices whenever the master and mezzanine boards are rearranged.