| 摘要 |
PURPOSE:To prevent the discontinuation of CPU processing by checking whether another ROM address has no data, and informing that the mounting-of-ROM has a fault by error processing when the ROM has no data. CONSTITUTION:A CPU usually controls each part with a program of an ROM2 and then sometimes uses a programs of an ROM3 in accordance with jobs. In this case, the address of the ROM3 of the jumping destination is set to a word register 12 and the data on the address is read out and checked. If the read data is equal to an FF, it is decided that the ROM3 is not mounted. Then the jumping to the corresponding address is inhibited, and a speaker 10 is driven to generate an error sound. In such a case, the CPU1 restarts its working as long as the ROM3 is mounted correctly. If the read data is not equal to an FF, the jumping is carried out to the corresponding address to execute the program of the address.
|
