Hitachi DK32EJ - Ultrastar Series 36.9 GB Hard Drive Reference Manual page 134

2 DU
3
4 (MSB)
n
The Parameter Code field specifies which log parameter, data counter or list
parameter, is being transferred for that log page.
The DU, DS, TSD, ETC, TMC, and LP fields are together referred to as the
parameter control byte.
Bit 7 : DU (Disable Update) bit
The DU bit indicates the status of log parameter updating.
The updating is done in the internal memory of the embedded controller.
Therefore, if the updating is not yet saved to the disk, requested by the initiator
or done by the drive automatically, the updated parameter values will be lost
during a power failure.
-- LOG SELECT usage -- :
For cumulative log parameter values the DU bit is defined as follows :
A zero value of DU bit indicates that the drive will increment the cumulative log
parameter value whenever an event should be noted by that parameter.
A one value of DU bit indicates that the drive will not update the log parameter
value except in response to a LOG SELECT command that specifies a new value
for the parameter.
The DU bit is not defined for threshold values nor for list parameters.
The drive will ignore the value of any DU bits in a LOG SELECT command.
To update the current threshold values , just pass the new value in the
parameter value field and specify the PC field to 00
LOG SELECT:(4Ch)
6 COMMAND DESCRIPTIONS
Table 6-21 Log Parameter (cont'd)
DS TSD ETC
Parameter Length (n-3)
Parameter Value
OEM MANUAL:K6602771
TMC LBIN
.
B
Revision: 2 / Date: 2002.12.19
LP
(LSB)
Page: 134 / 313