Patent ID: 7870428
Filing Date: 2011-01-11
Classification: G06F

Abstract:
1. A method of diagnosing a circuit board having a plurality of CPUs mounted thereon, the method comprising the steps of: sending interruption signals by a host CPU; receiving, by the plurality of CPUs, the interruption signals sent from the host CPU; performing ordinary circuit operations, based on the interruption signals from the host CPU, by respective task processing units included in the plurality of CPUs; outputting task signals, which indicate respective task statuses of the plurality of CPUs, by respective monitor units provided in the plurality of CPUs and operated separately from the task processing units; comparing and judging, based on the task signals outputted from the respective monitor units of the plurality of CPUs, combinations of the task statuses of the plurality of CPUs by a single diagnosis circuit connected in common to each of the plurality of CPUs; and detecting, based on comparison and judgment results, false operations and failures of the circuit board.