| 摘要 |
PURPOSE:To detect the normal operation of each unit by discriminating whether data written in a register is correct or not by comparison in a comparing circuit provided in the unit, and outputting the comparison result at the time of diagnosing. CONSTITUTION:A signal S indicating diagnosis is supplied to recognizing means 1-1 to 3-1 of respective units 1 to 3, recognizing means 1-1 to 3-1 recognize the diagnostic indication to output a diagnostic detection signal to comparing means 1-2 to 3-2. Comparing means 1-2 to 3-2 compare preliminarily set data and values in registers of units with each other by these signals. Since units 1 to 3 perform the diagnostic operation when the diagnostic indication signal S is supplied and is recognized as the diagnostic indication by diagnostic recognition means 1-1 to 3-1, comparing means 1 output comparison results with each of units 1 to 3 as the unit. At such a time, the actual processing operation is not performed but the diagnostic operation is performed. Thus, trouble signals outputted from units 1 to 3 are discriminated to find the unit where trouble occurs. |
