| 摘要 |
PURPOSE:To shorten the readout time, by changing an access switching means when a microinstruction to be read out does not exist in a control memory and performing the readout in parallel with the loading of a block containing a microinstruction word. CONSTITUTION:The inside of a secondary storage 1 is divided into blocks in advance and the inside of a control memory address array 5 is made to correspond to the blocks in the secondary storage 1. Moreover, the inside of a control memory 2 also divided into blocks and it is so arranged that data in the direction of row of the secondary storage 1 are read out and stored in the blocks in the direction of row of the control memory, in advance. Address information from a control instruction 4 is compared 6 with information from the address array 5 and, when a desired microinstruction exists, access 7 is made. When no desired microinstruction exists, the output of an access control circuit 8 is made effective by instructing the control circuit 4 from the comparator 6 and a block containing a desired microinstruction word is read out to a microinstruction register 3 from the secondary storage 1. Therefore, the readout time can be shortened. |
