HGST HUS724040ALS640 User Manual

HGST Ultrastar 7K4000 (SAS) Hard Disk Drive Specification
254
18.52 WRITE (10) - (2A)
Table 215: WRITE (10) - (2A)
The WRITE (10) command requests that the drive write the data transferred from the Initiator. This command is processed like
the standard WRITE (6) - (0A) command except for the longer transfer length.
• Transfer Length is the number of contiguous blocks to be transferred. If the transfer length is zero, the seek occurs,
but no data is transferred. This condition is not considered an error.
• DPO (Disable Page Out) bit of one indicates that the data accessed by this command is to be assigned the lowest pri-
ority for being written into or retained by the cache. A DPO bit of one overrides any retention priority specified in the
Mode Select Page 8 Caching Parameters. A DPO bit of zero indicates that the priority is determined by the retention
priority. The Initiator should set the DPO bit when the blocks written by this command are not likely to be read in the
near future.
• FUA (Force Unit Access) bit of one indicates that the Target must write the data to the media before returning Good
status. A FUA bit of zero indicates that the Target may return Good status prior to writing the data to the media.
• FUA_NV (Force Unit Access Non-Volatile Cache) may be set to 0 or 1, but is ignored since NV_SUP=0 in Inquiry
Page 86h.
If a WRITE(6) command is received after protection information is enabled, the drive will set the protection information as
follows as it writes each block to disk:
• the Logical Block Guard field is set to a properly generated CRC
• the Logical Block Reference Tag field is set to:
- the least significant four bytes of the LBA, if the drive is formatted with type 1 protection (PROT_EN=1 and
P_TYPE=000b in the READ CAPACITY (16) parameter data); or
- FFFFFFFFh, if the drive is formatted with type 2 protection (PROT_EN=1 and P_TYPE=001b in the READ
CAPACITY (16) parameter data)
• the Logical Block Application Tag field is set to
- FFFFh, if the ATO bit is set to one in Mode Page 0Ah; or
- Any value, if the ATO bit is set to zero
Byte
Bit
76543210
0 Command Code = 2Ah
1 WRPROTECT DPO FUA Rsvd=0
FUA_N
V
Obso-
lete
2-5
(MSB)
Logical Block Address
(LSB)
6 Reserved = 0
7-8
(MSB Transfer Length
(LSB)
9 VU = 0 Reserved = 0 FLAG LINK

HGST HUS724040ALS640 Specifications

General

Brand	HGST
Model	HUS724040ALS640
Category	Storage
Language	English