To decrease the number of bits in an execution condition field against the condition number by executing an instruction when the coincidence is confirmed between the decoding result of an execution condition code part and the condition that is set by a general-purpose flag.
An execution condition decoding part 401 extracts an execution condition field of an instruction and decodes the value of extracted three bits into the data corresponding to an execution control flag. If the value of three bits are equal to '000', the relevant code shows that it always executes the instructions. Thereby, the data are outputted to show that the execution control flag is ignored. An execution condition decision part 402 compares these data with the execution control flag. In such cases, the execution control flag is ignored and therefore the part 402 instructs an execution control part 403 to execute the relevant instruction. In response to this instruction, the part 403 outputs a control signal to a memory unit or an integer arithmetic unit.
YOSHIDA TOYOHIKO
KENGAKU TOORU
