| 摘要 |
PURPOSE:To reduce the load on a host device by accessing an external device when trouble occurs to a cache and accessing a target data block on the external storage device when a target process can be substituted. CONSTITUTION:A controller 2 is equipped with the cache 4 between a main memory device and the external memory device 3, a flag 241 which indicates whether access is already attained or not is provided for a cache trouble monitoring part 26 and the device 3, and a part which controls data transfer between the host controller 1, and the device 3 and cache 4 is further provided. Then, the monitor part 26 when detects the trouble of the cache 4 confirms the flag 241, when the device 43 is not accessed, the device 3 is accessed and when the device 3 is accessed, the device 1 is informed after its normal end as if the cache 1 were not accessed.
|
