| 摘要 |
PURPOSE:To improve the reliability, by dividing a storage device to two blocks and exchanging two logical blocks to be written in respective blocks in accordance with the internal state of a fixed fault and storing them when the fixed fault occurs in the storage device. CONSTITUTION:When a program is loaded to a control storage device CS1, written contents are read out again and are checked. If errors are detected, the same contents are loaded again and are checked; and if errors are detected though this loading is performed plural times, the occurrence of the fixed fault is discriminated. Since the fixed fault is the degeneration fault where only ''0'' or ''1'' is read out independently of written data, data having the degenerated value is written. The device CS1 is divided to two blocks A and B; and when the fixed fault exists in the block A, the logical block to be written in the block A is written in the block B. Thus, the fixed fault is recovered. |
