METHOD AND APPARATUS FOR COMPLETELY MAINTAINING DUAL MICROPROCESSOR MULTIPLE PROCESSING CALCULATION SYSTEM

摘要

A dual microprocessor computing system is used to control an engine in a motor vehicle. Each system contains a Personality Programmable Read Only Memory (PPROM) containing system calibration data that is transferred from the PPROM to the read-write memories in the microprocessors. In order to identify each PPROM a byte of memory contains a check sum and a byte of the microprocessor memory contains an identical check sum. During data transfer, the check sums are compared. Also during data transfer, the amount of data being transferred within a predetermined interval is counted both at the transmitter and the receiver memories.