| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly reliable data processor having resistance against trouble by making a secure recovery from troubles due to bugs of a program run on the data processor. SOLUTION: Firmwares 40A to 40n which have an identical function, but represented by different codings are stored in ROMs 30A to 30n respectively. A switching means 32 selects one ROM according to firmware discrimination information in a nonvolatile memory 24, and reads the firmware out of the ROM 30 and writes it to a RAM 22. A CPU 20 executes the firmware stored in the RAM 22. A monitor device 26 once detecting a fault halfway in the execution of the firmware stores discrimination information on a firmware 40 which is different from the others in the nonvolatile memory 24 and reactivates the processor. The reactivated firmware generally includes none of a bus which has caused trouble so far, thus a fault recovery is ensured. |
