Fujitsu MHE2064AT, MHF2043AT, MHE2043AT, MHF2021AT manual Usage of read segment, Mis-hit no hit

Operations

−READ MULTIPLE

−WRITE SECTOR(S)

−WRITE MULTIPLE

−WRITE VERIFY SECTOR(S)

3)Caching operation is inhibited by the SET FEATURES command.

4)Issued command is terminated with an error.

5)Soft reset or hard reset occurs, or power is turned off.

6)The device enters the sleep mode.

7)Under the state that the write data is kept in the data buffer for write command as a caching data, new write command is issued. (write data kept until now are invalidated)

6.5.3Usage of read segment

This subsection explains the usage of the read segment buffer at following cases.

6.5.3.1 Mis-hit (no hit)

A lead block of the read-requested data is not stored in the data buffer. The requested data is read from the disk media.

The read-ahead operation is performed only when the last sector address of the previous read command and the lead sector address of this read command is sequential (see item (2)).

1)Sets the host address pointer (HAP) and the disk address pointer (DAP) to the lead of segment.

HAP

Segment only for read

DAP

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