Data error detection and device controller failure detection in an

Abstract

A multiprocessor system of the kind in which two or more separate processor modules are interconnected for parallel processing includes interprocessor buses dedicated exclusively to interprocessor communication. The multiprocessor system includes an input/output system having multi-port device controllers and input/output buses connecting each device controller for access by the input/output channels of at least two different processor modules. Each device controller includes logic which insures that only one port is selected for access at a time. An enable latch in each port dynamically disables that port from placing any signals on the related input/output bus in response to a failure of any portion of the device controller, and the enable latch is not responsive to the processor module for re-enabling the port. The device controller controls the transfer of information between a processor module and a peripheral device, and information is gated into a register in a port in a device controller in response to a gating signal generated by a processor module. Parity generation and check means continuously monitor parity for the duration of the gating signal.