Data processing system with memory access priority control.

摘要

A data processing system including a plurality of multi-processor systems, each multi-processor system having at least one central processing unit (CPU0, CPU1; CPU2,CPU3) and at least one main memory (MEM0, MEM1; MEM2,MEM3) both connected to a memory control unit (MCU0,MCU1). Each memory control unit (e.g. MCU0) is connected to each other memory control unit (e.g. MCU1) and comprises plural ports (P0P0,P0P1, P1P0,P1P1), plural registers (RP0...RP3), access selection circuits (31,32) for inner and outer access, a priority control circuit (33), a first and a second control circuit (40,50) and a wait signal reset circuit (37). A priority of accesses from the same central processing unit to the other multi-processor system is detected, and the registers (RP) for storing the access request signals in the other multi-processor system are efficiently used by adding a priority control signal to the access request signal. Thus, the data throughput of the system and the access speed are improved.