| 摘要 |
PURPOSE:To detect immediately a faulty gate circuit by providing a counter within a device to be tested to count the shift number of clocks and referring to the count number from the count starting time point in a test mode. CONSTITUTION:A counter 11 exclusive for fault check is incorporated into a device 1 to be tested, and the count value of the counter 11 is displayed. This counter 11 is updated with the scan clock and receives +1 every time FF trains 1-1-1-N are shifted by a bit. Then the counter 11 is reset as soon as the FF train is reset, and the count value is set so as to have the complete coincidence with the FF train. As a result, a faulty FF can be immediately detected from the count value of the counter 11. |
