User Manual

SCSI Commands Reference Manual, Rev. J 422
www.seagate.com Parameters for direct access devices
5.3.20 Power Condition mode page (1Ah)
The Power Condition mode page provides an application client with methods to control the power condition of a logical unit
(see SPC-5). These methods include:
a) Specifying that the logical unit transition to a power condition without delay; and
b) Activating and setting of idle condition and standby condition timers to specify that the logical unit wait for a period of
inactivity before transitioning to a specified power condition.
The mode page policy (see 3.9) for this mode page shall be shared.
When a device server receives a command while in a power condition based on a setting in the Power Condition mode page, the
logical unit shall transition to the power condition that allows the command to be processed. If either the idle condition timer or
the standby condition timer has been set, then they shall be reset on receipt of the command. On completion of the command,
the timer(s) shall be started.
Logical units that contain cache memory shall write all cached data to the medium for the logical unit (e.g.,as a logical unit does
in response to a SYNCHRONIZE CACHE command as described in 3.51 and 3.52) prior to entering into any power condition that
prevents accessing the media (e.g., before a hard drive stops its spindle motor during transition to the standby power condition).
The logical unit shall use the values in the Power Condition mode page to control its power condition after a power on or a hard
reset until a START STOP UNIT command setting a power condition is received.
Table 397 defines the Power Condition mode page.
PS bit, SPF bit, PAGE CODE field, and PAGE LENGTH field
The PS bit, SPF bit, PAGE CODE field, and PAGE LENGTH field are described in 5.3.5.
Table 397 Power Condition mode page
Bit
Byte
7 6 5 4 3 2 1 0
0 PS SPF (0b) PAGE CODE (1Ah)
1 PAGE LENGTH (26h)
2 PM_BG_PRECEDENCE Reserved STANDBY_Y
3 Reserved IDLE_C IDLE_B IDLE_A STANDBY_Z
4 (MSB)
IDLE_A CONDITION TIMER. . .
7 (LSB)
8 (MSB)
STANDBY_Z CONDITION TIMER. . .
11 (LSB)
12 (MSB)
IDLE_B CONDITION TIMER. . .
15 (LSB)
16 (MSB)
IDLE_C CONDITION TIMER. . .
19 (LSB)
20 (MSB)
STANDBY_Y CONDITION TIMER. . .
23 (LSB)
24
Reserved. . .
38
39 CCF_IDLE CCF_STANDBY CCF_STOPPED Reserved