| 摘要 |
A microprogram control system of the invention has a mapping read only memory storing the respective initial addresses of a plurality of microprogram routines corresponding to a macroinstruction. The address input information to this mapping read only memory is obtained from an output of a binary counter which counts every time a JUMP instruction for making a branch to another microprogram routine is decoded, and from an output of a latch circuit for holding the operation code of the macroinstruction. When the microprogram routine has loops, a count inhibit signal is input to the binary counter so that the same address input information may be supplied to the mapping read only memory.
|
