| 摘要 |
PURPOSE:To shorten the checking time of normality in the loading of a microprogram to a subsystem and to improve the reliability of operation by forming a circuit for executing cyclic redundancy checking operation. CONSTITUTION:Cyclic redundancy check (CRC) operation data in the subsystems 21, 2n of microprograms are denoted as CRC1 and CRC2 respectively. When a transmission/reception control part 13 in the CPU1 transmits all data, CRC checking data are sent to the subsystem 21. A CRC control part 161 compares the sent CRC checking data with the CRC1, and at the time of coincidence, compares the sent CRC checking data with the CRC2 of the subsystem 2n. When all the data coincide with each other, the CRC control part 161 outputs an OK response. The OK response indicates the normal loading of the microprogram and the inconsistency of data indicates abnormal loading. Thus, the provision of the CRC operation circuit shortens the checking time of the loading of the microprogram to the subsystem and improves the reliability. |
