| 摘要 |
PURPOSE:To reserve the state of a central processing unit(CPU) until fault occurs by saving the contents of a register before updating. CONSTITUTION:When a control part 5 recognizes the occurrence of a fault, a register restoration instruction is issued to a receding buffer part 3 and address information stored in a location pointed out by buffer reading address register 310 is set up in an address register 1 from a saving buffer 300 and data are set up in a data writing register 210. A register part 2 restores the contents of the register 210 in the position pointed out by the register 1 by a write signal 22. At this time, the contents of the register 310 in the receding buffer part 3 are compared with that of the register 320 by a comparator 340, and when both contents are equal to each other, the restoration processing is ended and a restoration end signal 341 is outputted. When both the values are different from each other, the restoration processing is repeated. Consequent ly, the register destructed by the generation of the fault can easily be restored and the reliability of the whole system can be improved. |
