Fujitsu MHN2150AT Manual/User Guide - Page 216

Usage of read segment, sequential see item 2.

Page 216 highlights

Operations 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) 6.4.3 Usage of read segment This subsection explains the usage of the read segment buffer at following cases. 6.4.3.1 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 2) Transfers the requested data that already read to the host system with reading the requested data from the disk media. HAP Stores the read-requested data upto this point Read-requested data Empty area DAP 6-14 C141-E120-02EN

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Operations
6-14
C141-E120-02EN
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)
6.4.3
Usage of read segment
This subsection explains the usage of the read segment buffer at following cases.
6.4.3.1
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.
Segment only for read
DAP
HAP
2)
Transfers the requested data that already read to the host system with reading
the requested data from the disk media.
Read-requested data
Stores the read-requested
data upto this point
Empty area
DAP
HAP