Digital data processing methods and apparatus for fault detection and fault tolerance

摘要

A digital data processing device includes a bus for transmitting signals (e.g., data and/or address information) between plural functional units (e.g., a central processing unit and a peripheral controller). A first such unit includes first and second processing sections that concurrently apply to the bus complementary portions of like information signals (e.g., longwords containing data). A fault detection element reads the resultant signal from the bus and compares it with at least portions of the corresponding signals originally generated by the processing sections themselves. If there is discrepancy, the fault-detector signals a fault, e.g., causing the unit to be taken off-line. By use of a redundant unit, processing can continue for fault-tolerant operation.