| 摘要 |
PURPOSE:To shorten the access selecting time by providing two output terminals for DS signals and a selection circuit which decides one of two DS signals that should be validated in a debugging microprocessor. CONSTITUTION:A debugging microprocessor 1 is provided with the output terminals 3 and 4 for two DS signals 6 and 7 serving as a memory to especially receive an access and an I/O access selection circuit and a selection circuit 13 which validates the signal 6 or 7 based on the type of the program under execution or an instruction of the processor 1 and also invalidates the other one of both signals 6 and 7. Thus it is possible to shorten the time needed for decision an access destination in the processor 1 and also to design an in-circuit emulator 2 which has an operation more approximate to an actual microprocessor. |
