| 摘要 |
PURPOSE:To shorten the execution time of a drawback instruction by executing the drawback instruction after waiting for the end of the processing, when the drawback instruction is received in the course of processing an instruction whose execution time is short. CONSTITUTION:A microcomputer system is provided with two arithmetic circuits of a CPU (Central Processing Unit) 100 and a FPU (Floatingpoint Processing Unit) 101 in order to execute floating point arithmetic. In such a state, by dividing into an instruction whose execution time is long and an instruction whose execution time is short without executing a drawback instruction by always interrupting a processing by an instruction which is being executed, whether the execution of the drawback instruction is started by interrupting the processing, or the execution of the drawback instruction is started after waiting for the end of the processing executed by the instruction which is being executed is selected. In such a way, the execution time of the drawback instruction of the processor can be shortened. |
