| 摘要 |
PURPOSE:To change a specific field of a microcode which is under execution by latching temporarily the execution result of a microprogram and then selecting a part of the microcode or the latched contents. CONSTITUTION:The microcode is stored in a memory 1 and latched by a latch circuit 2 to be executed by a program executing circuit 3. The field of a bus D of the execution result is latched by a latch circuit 4 via a bus (d) and fed to a selection circuit 5 through a bus (e). Then the circuit 3 produces an indication signal through a line (c) to select the contents of the D bus field of the memory 1 or the contents of the D bus field of the circuit 4. If the indication signal indicates the selection of the output of the circuit 4, the circuit 5 selects the contents of the circuit 4. Therefore the circuit 2 fetches the contents out of the circuit 4. |
