Mode Page 08 (Caching Parameters); Table 82. Page 08 (Caching Parameters) - Hitachi HUS151473VL3800 - Ultrastar 73.4 GB Hard Drive Specifications

17.10.8 Mode Page 08 (Caching Parameters)

Table 82: Page 08 (Caching Parameters)
Byte
7
0 PS
1
2 IC
3 Demand Read Retention Priority
(MSB)
4-5
(MSB)
6-7
(MSB)
8-9
10-11
12 FSW
13
(MSB)
14-15
16
(MSB)
17-19
The caching parameters page defines parameters that affect the use of the cache.
• IC (Initiator Control) bit of one specifies that the drive will honor the following parameters to control cache
segmentation and pre-fetch: SIZE, FSW, LBCSS, Number of Cache Segments, Cache Segment Size. The drive will
never pre-fetch less data than specified by ABPF, MF, Demand Read Retention Priority, Write Retention Priority,
Disable Pre-fetch Transfer Length, Minimum Pre-fetch, Maximum Pre-fetch, and Maximum Pre-fetch Ceiling, but
may pre-fetch more based on internal cache algorithms. When the IC bit is set to zero, all the parameters listed above
are ignored, and an internal caching algorithm is used.
• ABPF (Abort Pre-fetch) bit of one, with DRA set to zero, causes the drive to abort the pre-fetch upon receipt of a new
command. ABPF set to one takes precedence over Minimum Pre-fetch. When ABPF is zero, with DRA set to zero,
the termination of any active pre-fetch is dependant upon the other parameters in this page.
• CAP (Caching Analysis Permitted ) is not supported and is ignored.
• DISC (Discontinuity) is not supported and is ignored.
• SIZE (Size Enable) bit when set to one indicates that the Cache Segment Size is to be used to control caching segmenta-
tion. When SIZE is set to zero, the Initiator requests that the Number of Cache Segments is to be used to control cach-
6 5 4
0
Page Length = 12h
ABPF CAP DISC
Disable Pre-fetch Transfer Length
Minimum Pre-fetch
Maximum Pre-fetch
Maximum Pre-fetch Ceiling
LBCSS DRA
Number of Cache Segments
Cache Segment Size
Reserved = 0
Non Cache Segment Size
Hitachi Ultrastar 15K147 SCSI Hard Disk Drive Specification
Bit
3 2
Page Code = 08h
SIZE WCE
Write Retention Priority
Reserved = 0
125
1 0 Default
88h
12h
MF RCD 04h
00h
FFh
(LSB)
00h
(LSB)
FFh
(LSB)
FFh
00h
08h
00h
(LSB)
00h
00h
(LSB)