| 摘要 |
PURPOSE:To easily diagnose a fault part in electronic equipment by operating only the part of a microprogram which becomes abnormal with an external clock with fault diagnosis. CONSTITUTION:Microinstructions read out of a microprogram memory 2 are executed one after another to control the electronic equipment. At this time, when externally set address data coincides with an address outputted by a microprogram sequence control circuit 1, a comparing circuit 6 outputs a coincidence signal to set an FF 7. Consequently, a selector 8 switches a clock supplied to the control circuit 1 and microinstruction registers 3a and 3b from an internal clock to an external clock. Therefore, the control circuit 1, registers 3a and 3b, and circuit 4 in the electronic equipment are held at the point of time and signals and states of respective parts are checked. Further, the external clock is applied, pulse by pulse, to make a check at every time. |
