PARITY CHECK SYSTEM OF MICROPROGRAM STORAGE MEMORY

摘要

PURPOSE:To shorten the processing time by generating addresses of a microprogram storage memory successively to read out a microprogram and performing parity check when specific information is sent from a central processing unit of a current system. CONSTITUTION:In case that a central processing unit 2 of a stand-by system is checked, a central processing unit 1 of the current system reads out control information from a main storage device 3 and sets it to a shift register 11. This information is set to a shift register 21 of the central processing unit 2 of the stand-by system. A sequence control part 26 starts the sequence of parity check when a parity check designating flip flop 25 is set. The sequence control part 26 outputs the microaddresses stored in a microprogram storage memory 27, and a parity check circuit 28 performs parity check of the outputted microprogram.