| 摘要 |
PURPOSE:To simply control the first step of a microprogram by providing a memory decoder to be exclusively used for controlling the 1st step and using the memory decoder together with the one for controlling the 2nd step on and after. CONSTITUTION:The 1st memory decoder 4 is exclusively used for the control of the 1st step of a microprogram. A selector circuit 6 selects the output of the 1st memory decoder 4 in case of controlling the 1st step of a microprogram to be executed in responce to each microinstruction to an operation processing device 8, and selects the output of the 2nd memory decoder 5 in case of controlling the 2nd step on and after of the microprogram. A control register 7 receives the output of the 1st memory decoder 4 or the 2nd memory decoder 5 selected by the selector circuit 6 and the output of the control register 7 controls the operation processing device 8. |
