| 摘要 |
PURPOSE:To detect easily a faulty part, by holding the contents before and after the occurrence of a fault as they are, when the fault occurs and contents of a system latch become dissident. CONSTITUTION:For instance, in case when a fault occurs in either combining circuits 1a, 1b or system latches 2a, 2b, a coincidence detecting circuit 7 outputs dissidence information. This dissidence information is inputted to a system clock obstructing circuit 8 together with a system clock. Accordingly, no system clock is provided to system latches 4a, 4b from the system clock obstructing circuit 8, therefore, a result of operations executed in a combining circuit 3a and 3b, respectively is not stored in the system latch 4a and 4b, and a state immediately before the occurrence of a fault remains as it is. In case when a fault occurs in either the combining circuits 3a, 3b or the system latches 4a, 4b, the processing is executed in the same way. |
