| 摘要 |
PURPOSE:To prevent the error of a flag bit from causing directly malfunction of a system by composing the flag of plural bits, and detecting its contents have priority between 1 and 0 and correcting the contents of the flag. CONSTITUTION:The flag 4 consists of plural bits, and the number of constituent bits and address value of one word in an ROM5 are equalized to those of the flag 4. The value of the flag 4 is used as an address specifying value to access the ROM5 and read the data out of the address, recognizing one value occupying more constituent bits as the real value of the flag 4. A data output 10 is sent out to the flag 4, whose contents are corrected into the value of the data output 10. |
