| 摘要 |
PURPOSE:To obtain a microprogram controller capable of reducing the number of accesses by half, improving reliability and executing also complex control and having superior expanding property and flexibility by changing the constitution of control storage and expanding the word length of a microinstruction up to twice the length of a reference microinstruction. CONSTITUTION:Microinstruction having odd addresses are successively stored in address of a control storage 3 and microinstructions having even addresses are successively stored in the addresses of a control storage 4. When an address is supplied from a microaddress forming circuit 2, two microinstructions stored in continued odd and even addresses are read out from the control storages 3, 4. The two microinstructions read out from the control storages 3, 5 are stored in microinstruction registers 5, 6 respectively, a part of the outputs from the registers 5, 6 in inputted to an address forming circuit 2 and the succeeding address if formed by decoding a next address instruction, a branch instruction or the like. On the other hand, microinstructions are outputted from the registers 5, 6 and the device is controlled in accordance with the kind of the instruction and the address.
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