| 摘要 |
PURPOSE:To recover an instantaneous fault of an RAM and to improve the reliability of a data processor by using an RAM and an EPROM to a program memory and a back-up memory respectively. CONSTITUTION:''1'' is added to the count value of a retrial counter every time a parity error FF9 is set. The contents of an address register 11 are supplied to an address back-up register 12. Then the contents of a back-up memory EPROM 5 are read out by the address given from the register 12 and then written to a program memory RAM4. In a retrial mode the contents of the RAM4 are read out by the address of the contents of the register 11 and then written to an instruction register 7 to perform a parity check. |
