| 摘要 |
PURPOSE:To detect errors of writing and reading easily, by providing a magnetic disk device with an adder and a nonvolatile memory and comparing the addition value of the adder with the addition value of the nonvolatile memory whenever data is written or read. CONSTITUTION:The adder 3 is connected to the internal bus 9 of the magnetic disk device to add read and written data to a disk, and the nonvolatile memory 6 is connected to store the addition value of every sector of the disk. When data is read out of the magnetic disk 1, the adder 3 is initialized and the address and length of the disk to be read are designated to a CPU4; and a direct memory access controller 7 is actuated and data is transferred, sector by sector, from the disk 1 to a data buffer 8. During the transfer, the adder 3 is actuated to sum up the data. The addition value stored in a nonvolatile memory 6 corresponding to a sector out of which the data is read is compared with the value of the adder 3 and when they are not coincident with each other, error processing is carried out. When data is written, it is processed similarly. |
