| 摘要 |
PURPOSE:To make change in an address unnecessary even when program change is required by reading a microinstruction from a designated memory address, executing it and reading/writing data to/from a memory address being 1's complement of the designated address by the same microinstruction. CONSTITUTION:The content of an instruction address register 1 is initialized to '0' and added by 1 block each to given the 1st memory address every every time the instruction is executed further. a selector 4 applies an address represented by the instruction address register 1 at read of the instruction to a memory 5 and outputs the content of the corresponding address to a microinstruction decoder 6. When the execution of the microprogram is started from the memory address 00, the content of the said register 1 is incremented from the 00 by 1 the microinstruction in the inside of the corresponding memory 5 is read to the decoder 6 sequentially via the selector 4 and executed. |
