Method and device for detecting and correcting error in pipeline type computer system

PURPOSE: To speedily and efficiently correct an error occurring during the operation of a CPU by providing a service processor, a scan controller, a scan distributor, a program counter, etc., and detecting and correcting the error. CONSTITUTION: The service processor SPU 42 detects the error through a serial diagnostic link including the scan controller SCM 44. If the error is detected, the CPU clock causing the error is stopped and the SCM 44 instructs the scan distributor SCD 45 to shifts information out of the CPU 12 and in the SCM 44. Once the information is copied from the CPU 12, a program counter PC 24 is set to a proper value, and held in the current state in the case of an asynchronous error and reset to the value corresponding to the instruction having caused the error in the case of a synchronous error. Then the CPU clock is restarted and the CPU 12 restarts the execution of the program. Consequently, the error during the operation of the CPU 12 is speedily and efficiently be corrected. COPYRIGHT: (C)1990,JPO