| 摘要 |
PURPOSE:To constitute so that access is executed to an actual store destination without changing a microprogram read-out address, even if a store destination of a microprogram is changed, in an information processing device for storing the microprogram in a control storage device and a main storage device. CONSTITUTION:When reading out a microprogram, in case when the most significant bit 1A is ''1'' among microprogram read-out address bits inputted to an address register 1, outputs of a gate 7 and a gate 8 become ''0'' and ''1'', respectively, irrespective of other input signal. In this case, a selecting circuit 5 selects a lower bit 1B of the microprogram read-out address bits held by the address register 1, and in accordance with this lower bit 1B, a main storage device B is subjected to access by the timing generated by a timing control circuit 9. A selecting circuit 8 sets a microprogram read out of the main storage device B to a micro-instruction register C. |
