摘要 |
A microprogrammed LSI microprocessor comprises a read only memory (ROM) for storing therein microprograms and a decode table for the operation code of macroinstructions, and an arithmetic logic control section constructed into a one package of LSI circuit. The arithmetic logic control section is constructed into a circuit arrangement which, on the assumption that the operation code of macroinstructions be an address, sets the starting address of a corresponding macroinstruction read from the ROM in a location counter, reads from the ROM a microinstruction corresponding to the starting address set in the location counter to set this microinstruction in a microinstruction register, and arithmetically executes the microinstruction stored in the microinstruction register. |