| 摘要 |
PURPOSE:To unerringly attain switching from a debugging program to a debugging object program for debug by outputting a response signal for debugging, which becomes active in the reset section period of internal information by means of the execution of a debugging instruction. CONSTITUTION:An instruction execution part 3 is provided with a micro code 11-1 executing a special instruction (RETB) for debugging. When the instruction is inputted via a bus control part 2, the execution part 3 decodes RETB and instructs the bus control part 2 of an action that is to read a program status word (PSW) and a program counter (PC) from a memory. At the same time, the bus control part 2 informs a reset instruction response control part for debugging 4 of a bus cycle for the reset action of PSW and PC as the execution of the RETB instruction. Thus, the reset instruction response control part 4 outputs an RETB signal which is synchronized with the bus cycle in the period of the bus cycle for the reset action of PSW and PC. Thus, possibility that the switching for the program for debugging is mistaken is eliminated. |
