4.1 Control/Sense Commands

4.1.15 LOG SELECT (4C)

Byte

Bit

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.

C141-C013

187

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Image 191
Fujitsu MBC2073RC, MBC2036RC, MBA3300RC, MBA3147RC, MBA3073RC specifications LOG Select 4C