Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
118
18.6
LOG SELECT (4C)
Table 91 Log Select (4C)
Byte
Bit
7
6
5
4
3
2
1
0
0
Command Code = 4Ch
1
Reserved = 0
Reserved = 0
PCR
SP
2
PC
Page Code
3
SubPage Code = 0
4-6
Reserved = 0
7
8
(MSB)
Parameter List Length = 0
(LSB)
9
Reserved = 0
FLAG
LINK
The LOG SELECT command provides a means for the Initiator to clear statistical information maintained by the drive
and reported via the LOG SENSE command.
- PCR The Parameter Code Reset determines whether the Log Sense parameters will be cleared and unit
attention posted for all other Initiators. A value of 1 indicates that the parameters be cleared, while a value of
zero (except when PC = 11b) indicates that the parameters not be cleared. Parameter list length must be zero
when PCR is 1.The PC field is ignored for list parameters, i.e. when the Format and Linking (F&L) field contains
01b or 11b.
- SP The Save Parameters bit value of zero indicates that the page parameters not be saved. A value of 1
indicates that the page parameters that are savable be saved after they have been changed. SP bit MUST be 1
if parameter list length is greater than zero. Otherwise it will result in a Check Condition status being returned.
The sense key shall be set to Illegal Request and additional sense code of Invalid Field in CDB.
- PC The Page Control field defines the type of parameters to be selected. The PC field set to 11b (and PCR is
then a don't care) indicates that the Default Cumulative values are set to their default values of 0. If the PC field
is set to 01b and PCR is set to 1, the Current Cumulative values are also set to their default values of 0.
Parameter List Length MUST be zero when PC = 11b. Otherwise the command is terminated and a Check
Condition status is returned. The sense key shall be set to Illegal Request and additional sense code of Invalid
Field in CDB.
- Page Code field identifies which page is being selected. This field must be set to the values indicated in Page 0.
If the Page Code value is invalid a Check Condition status is returned with a sense key of Illegal Request and
additional sense code of Invalid Field in CDB.
• If page code field is set to zero, then the selection applies to all log parameters in all valid log pages.
• If page code field is set to a non zero, then the selection applies to all log parameters specified by this field.
- SubPage Code This field specifies the subpage to select. This field is not supported and must be set to 0.
- Parameter List Length The Parameter List Length field specifies the length in bytes of the parameter list that
shall be located in the DATA OUT buffer. A parameter list length zero indicates that no pages shall be
transferred.
• If the PARAMETER LIST LENGTH field is set to zero, then the PCR bit, the SP bit, and the PC fields apply to
the page (pages) addressed by the page code field.
• If The PARAMETER LIST LENGTH field is set to non zero, and the if PAGE CODE field is non-zero or the
SUBPAGE CODE field is non-zero, then the command shall be terminated with CHECK CONDITION status,