| 摘要 |
PURPOSE:To improve the performance of a data processing device, by starting immdeiately the advanced processing of a special instruction when it is absolutely impossible that a register, which is used for instruction modification by the special instruction, is not rewritten by an instruction for which the advanced processing is executed. CONSTITUTION:When a special instruction is read out from a storage device 1 and is inputted to a D unit 3 for decoding instructions, the unit 3 detects that the read instruction is the special instruction and the unit 3 not only sets the address of a general register 12 used for modification to a register 11 but also starts the device to read an instruction to be modified. When the read of the instruction to be modified is completed, the device 1 reports a read completion signal to a D control part 7. The control part 7 confirms transfers a strart command of an instruction processing D to the unit after confirming that this read is completed and that the preceding instruction in course of processing does not rewrite contents of the register 12. The unit 3 inputs the instruction to be modified and reads out modification contents from the register 12 and modifeds the instructions to generate an instruction to be executed and performs a processing in accordinace with this instruction. |
