| 摘要 |
PURPOSE:To attain the simple checking of buses with no increase of the hardware quantity by reading the data written previously when a power supply is applied and using the difference from a writing mode to check a bus. CONSTITUTION:The check data is written to a data area 5 by the program of a central processing unit 3 in an initial register mode of a microdisk device 4. Then the check data is read when a system power supply is applied and compared with the writing data obtained in the initial register mode according to the program of the unit 3. It is decided that a bus has the abnormality if a difference is obtained from said comparison. Thus the bus can be easily checked without increasing the hardware quantity. |
