| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly reliable data processor with excellent failure resistance so as to realize a failsoft by surely operating while suppressing the degeneration of a function even at the time of occurrence of a failure caused by a bug in a program to be executed by a data processor. SOLUTION: Normal operation firmware 40A and firmware for degeneration operation at the time of a failure 40B expressed in mutually different coding are housed in ROM 30A and 30B respectively. The firmware 40B is provided only with a required function being a part of the function of the firmware 40A. At first the firmware 40A is executed, but when a failure occurs, a switching means 32 switches to the execution of the firmware 40B read from ROM 30B. As the firmwares 40A and 40B do not share a bug with each other, the failure is removed. |
