IMPORTANT DATA PROTECTING METHOD FOR MAIN STORAGE DEVICE

摘要

PURPOSE: To shorten processing time and to reduce error by informing an interrupting signal and important data of a program when a protecting memory bit is turned on and a memory access signal is commanded to a relevant address. ;CONSTITUTION: A signal MEM to make access to a main storage device 1 and a signal PMEM to make access to a protective memory bit 2 are ORed by an OR circuit 4 and defined as the access signal of the protective memory bit 2. A read/write instructing signal RW and the signal MEM are ORed by an OR circuit 3 and defined as a signal to designate the read/write of the protective memory bit. The signal MEM and protective memory data PD of one bit corresponding to a memory address signal An are ORed by an A/D circuit 5 and defined as an interrupting signal INT. Then, the protective memory bit corresponding to the address storing the important data is turned on by a program in advance. Therefore, in the case of accessing the important data, it is informed by the interrupting signal INT and accordingly, the program processes it as the important data.;COPYRIGHT: (C)1993,JPO&Japio