Majority circuit and control unit and semiconductor integrated circuit null for majority

摘要

This invention provides a majority circuit, connecting a plurality of processing units. The majority circuit can detect a single error or multiple errors, and sets the majority output signal to an ineffective level when multiple errors are detected. The majority circuit includes comparators, each comparing two outputs of three processing units, and the error detector recognizes the error status and outputs the single error signal and the multiple error signal accordingly. The majority circuit also includes a selector, which selects the output of a normal processing unit, when the normal processing unit can be specified based on the comparison result. The selector changes the output to a predetermined level, when the normal processing unit cannot be specified.