| 摘要 |
PURPOSE:To enable to bypass sum check routine in the case of a specified value by setting a reference area for writing selectively in a memory either the specfied value or sum value besides a work area. CONSTITUTION:Sum check of a memory is performed by referring to the reference area R when a power source is made on, obtaining the sum from 0 address to 1B00 address when the value is other than FF, and judging whether lower two digits coincide with the reference area R. When the value written in the reference area R is FF, sum check routine is bypassed, and ordinary processing is continued deciding that the memory is normal. In the case where it is necessary to change the content of program temporarily, FF is written in the reference area R. Thus, it becomes unnecessary to execute sum check routine every time, and maintainability is improved. |
