| 摘要 |
PURPOSE:To easily point a trouble position by writing different data in two specific storage elements of cascaded maintenance replacement units and shifting out data stored in each replacement unit. CONSTITUTION:If trouble of storage elements in shift registers 1-3 is detected, a shift-out output control circuit 9 outputs an error report signal to a maintenance diagnosing device 10 to report this trouble. This device 10 outputs a control signal 113 to an input control circuit 12, and input circuits 13 and 14 are controlled by a control signal 113 to write '1' and '0' in two specific storage elements of shift registers 1-3. When the scan-out operation is executed in registers 1-3 thereafter, contents stores in each register are transferred to a shift buffer 11. The maintenance diagnosing device 10 reads out and checks data transferred from registers. |
