| 摘要 |
PURPOSE:To detect errors efficiently by loading a correct data to an ROM data register when scanning parity check operation is stopped once because of error detecting and then starting the operation again. CONSTITUTION:The titled system is provided with an ROM1 in which microprograms are stored, an ROM data register 2 in wich the micro-instructions are written, a parity check circuit 3, etc. The circuit 3 always executes the parity ckeck of an output of a circuit 2 and, when detecting a parity check error, the circuit 3 drives a control circuit 7 to stop a clock signal for loading. When a correct data which generates no parity error is loaded in the register 2, the output of the circuit 3 indicates no parity error, so that a circuit 7 outputs loading clocks again to the register 2 and the address register 6 to start scanning operation. |
