| 摘要 |
PURPOSE:To prevent an error due to variance in operation speed by setting the timing of sampling for comparison to two different points with regard to a device which compares a reference circuit and a logical circuit to be diagnosed with each other and conducts a test. CONSTITUTION:Signals from the reference circuit 2 and logical circuit 1 to be diagnosed are led to a memory circuit 6 and a selecting circuits 9 and 10 through receiver circuits 4 and 3 respectively. The selecting circuits 9 and 10 select the signals from the receiver circuits 4 and 3 and timing signals T1 and T2 with a selection signal S, and either of the diagnosed logical circuit output and reference circuit output is stored in a memory 5 at timing T1 pr T2. The outputs of the memory circuits 5 and 6 are compared with each other by a comparing circuit 7, and the comparison result is inputted to a processing part 8. The memory circuit 6 fetches a signal (a) at the timing T1 and the memory circuit 5 fetches the reference circuit signal (a) at the timing T2 with the selection signal S as shown in a time chart, so a dissidence signal (d) is outputted when the signal (a) varies with the timing signals T1 and T2. |
