| 摘要 |
PURPOSE:To avoid the breakdown of a disk access control system by adding a nonvolatile memory into a disk device to store the data under a write mode into the disk device so that the data can be rewritten despite occurrence of the power supply abnormality like a hit, etc. CONSTITUTION:A DMA interruption control part 1-1 is started by the information given from a CPU 5 and transfers the data read out of a memory 4 to an NV 2-4. In this case, a RAM 2-3 stores an unwritten flag that shows whether the disk address, the NVM address and data are written into a disk device 3 or not. In case the power supply abnormality occurs in a data write mode, the data stored in the NVM 2-4 corresponding to the ON state of said unwritten flag is written into the device 3 after the second application of the power supply. Thus, it is possible to avoid the destruction of data and to improve the system reliability. |
