6.6 Write Cache

The drive uses a cache data of the last write command as a read cache data. When a read command is issued to the same address after the write command (cache hit), the read operation to the disk medium is not performed.

If an error occurs during the write operation, the device retries the processing. If the error cannot be recovered by retry, automatic alternate assignment is performed. For details about automate alternate assignment, see item (3) of Section 6.4.2.

The write cache function is operated with the following command.

WRITE SECTOR(S)

WRITE MULTIPLE

WRITE DMA

When Write Cache is permitted, the writing of the data transferred from the host by the abovementioned Write Cache permit command into the disk medium may not be completed at the moment a normal ending interrupt has occurred.

In case a non-recoverable error has occurred during receiving more than one write command, it is difficult for the host to identify a command that caused the error.

(However, the error is not reported to the hose if an error at writing has been processed normally.)

Therefore, note that it is difficult for the host to retry an operation that caused a non-recoverable error.

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Fujitsu MHK2120AT, MHK2090AT, MHK2060AT, MHJ2181AT manual Write Sectors Write Multiple Write DMA