MainBrain Hardware Reference

MainBrain is a small high performance M4K processor based main board that interfaces to a 'stack' of secondary boards whos configuration is determined by the developer. High speed communication between MainBrain32 and the secondary boards is achieved through a dual RAM port. This creates a 1,024 (1K x 8) register bank that can be continually updated by the MCU and read by the interface boards at the same time. The two RAM ports are provided with separate control, address and I/O pins that permit independent access for reads or writes to any location in port memory. One port is accessed by the MCU while the second port is accessed by the interface board(s). Busy Logic provides a hardware indication that both ports of the SRAM have accessed the same location at the same time. It also allows one of the two accesses to proceed and signals the other side that the SRAM is busy.