| 摘要 |
PURPOSE:To omit the duplication of plural address comparators by inputting inspection address data to the comparators at the timing when the address comparators need not to execute their substantial comparing operation. CONSTITUTION:An inspection data forming circuit 2 forms inspection address data 105, 106 and a timing detecting circuit 1 detects the timing when the address comparators 13, 23, 33 need not execute their substantial address comparing operation. At the timing, the inspection address data 105, 106 are inputted to the address comparators 13, 23, 33. Failure deciding circuits 14, 24, 34 monitor the outputs of the address comparators 13, 23, 33 at that timing and discriminate the presence of faults. Thus, the faults of the address comparators 13, 23, 33 can be detected without duplicating the address comparators 13, 23, 33. |
