User's Manual

4.1 Control/Sense Commands
4.1.15 LOG SELECT (4C)
Bit
Byte
7 6 5 4 3 2 1 0
0 X'4C'
1
0 0 0 0 0
0 PCR SP
2 PC
0 0 0 0 0
0
3
0 0 0 0 0 0 0
0
4
0 0 0 0 0 0 0
0
5
0 0 0 0 0 0 0
0
6
0 0 0 0 0 0 0
0
7 Parameter List Length (MSB)
8 Parameter List Length (LSB)
9 0 0
0 0 0
0
0
0
This command provides a means for an application client to manage statistical
information maintained by the HDD about HDD. The INIT can know the types of
statistical information and the current maintaining of each statistical information
by using the LOG SENSE command.
A "Save Parameters (SP)" bit is one indicates that after performing the specified
LOG SELECT operation the drive will save all parameters to the disc medium. A
"SP" bit of zero specifies that parameters are not saved. It is not an error to set the
"SP" bit to one and to set the DS bit of a log parameter to one. In this case, the
parameter value for that log parameter is not saved.
The "Parameter Code Reset (PCR)" bit of one and a "Parameter list length" of zero
cause all implemented parameters to be set to zero. It also clears the SMART
Failure Warning and the Thermal Warning. If the "PCR" bit is one and the
parameter list length is greater than zero, the command is terminated with CHECK
CONDITION status (ILLEGAL REQUEST [=5] / INVALID FIELD IN CDB
[=24-00]). In this case, the log parameters are not cleared. A PCR bit of zero
specifies that the log parameters are not reset.
The "Page Control (PC)" bits specify a kind and treatment content of parameters
that changed by this command as shown in Table 4.19.
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