| 摘要 |
PURPOSE:To reduce the capacity of a control memory for a microprogram control device, by securing the replacement of microinstructions of different parts for those having similar contents of routine processes. CONSTITUTION:The 1st control memory 1 stores a microprogram, and the 2nd control memory 2 has a shorter word length and smaller number of words than the memory 1. The memory 2 is addressed by a part of the output of a microinstructions address register 6. A switching control circuit 5 controls a switching circuit 3 and then supplies the microinstruction read out of the memory 1 directly to a microinstruction register 4 or supplies a part of the microinstruction to the register 4 after replacing it with the contents read out of the memory 2. |
