| 摘要 |
PURPOSE:To shorten the necessary time of error processing, by making an error check every time one word is written during loading into the control memory of a microprogram controller, and switching a controller when the frequency of error occurrence exceeds a reference value. CONSTITUTION:A microprogram MP controller 1 receives an initial MP loading (IMPL) instruction to store external data in a register 4 and performs encoding 5 to generate a check correction code, which is stored in a register 6. The data in both registers 4 and 6 are written in a control memory 2. Then, contents read in a register 7 are sent to a detecting circuit 8 to discriminate on whether a one-bit error occurs or not; when the error is found, its correction result is set in the register 7 again and a counter 9 is driven. When the MP is all loaded in the control memory 2, data is read out 7 and decoded 11. The output of a decoder 11 is held in a work register 10 by sampling the counter 9 by a gate 12. When the value of the counter 9 is greater than the specific value, a decision on a failure in IMPL is made and a controller 200 is excluded. |
