| 摘要 |
PURPOSE:To decrease the length of a microinstruction and the number of steps, by controlling a control item which can be performed by giving a prescribed control to the hardware depending on characteristics of an instruction read out from a main storage device, with an auxiliary control code. CONSTITUTION:An instruction read out from a main storage device is stored in an instruction register 1 and the content of a conversion memory 3 is read out by taking an instruction code 2 in the instruction register 1 as an address. A part of the read-out content is a microinstruction address 7 and the rest is an auxiliary control code 8 and stored in an auxiliary control register 9. The hardware controls the operation depending on the content of the register 9. The code 8 stored in the register 9 remains unchanged independently of the revision of a micro program counter 6, until a new instruction is read out to the register 1 from the main storage device. |
