| 摘要 |
PURPOSE:To execute highly accurate diagnoses, by causing an instruction buffer to hold data outputted from an arithmetic logical operation circuit instead of data read out from a memory and loading the held data onto an instruction processing section. CONSTITUTION:When the 1st microinstruction 600 is outputted, a selector 8 selectively passes data 400 from an arithmetic logical operation circuit 7 through an ALUI and outputs the data 400 to a RIB 1. When the 2nd microinstruction 800 is outputted to the RIB 1 thereafter, the data held by the RIB 1 are loaded onto and processed by an instruction processing section 5. A RIB checking circuit 6 simultaneously outputs a read request signal 200 to a gate 9 when detecting that the RIB 1 becomes vacant, but, since a flip flop 10 is set by the 2nd microinstruction 800, passing of the signal 200 through the gate 9 is checked. Therefore, no bus controlling signal is inputted to a bus controller 3 and, as a result, readout of instructions from a memory 2 is eliminated. |
