| 摘要 |
PURPOSE:To prevent an important fault from being given to a device, by not executing extended instructions sent by the control storage device but executing the program of error occurrence when the error occurs in stored contents of the rewritable control storage device by saving or rewrite processing. CONSTITUTION:A data processor consists of the control storage device CS consisting of an ROM and a rewritable control storage device WCS10; and when power break or initializing occurs, contents of the WCS control table, the execution mode preserving address, this execution area, etc. of the WCS10 are saved in fixed addresses of the main storage device. At the power break recovery or initializing end time, contents of fixed addresses in the main storage device are rewritten by a memory data register 21, a selector 23, a WCS address register 11, etc. At this time, control information and instruction type designating information of upper bits of the WCS 10 are delected and are set to 0. This processing is performed by the program from the control storage device, and extended instructions are not executed. |
