Table 73 Extended Power Conditions Subcommands; Table 74 Power Condition Ids; Extended Power Conditions (Epc) Feature - Western Digital Ultrastar DC HC310 Specifications

9.19

Extended Power Conditions (EPC) Feature

The Extended Power Conditions feature set provides a host with additional methods to control the power condition of
a device.
Subcommand code 4Ah enables, disables, and configures the use of the Extended Power Conditions feature set. If
the EPC feature set is not supported, then the device return command aborted Table 73 describes the EPC
subcommands and Table 74 describes the power condition IDs.
EPC Subcommand
0h
1h
2h
3h
4h
5h
6h ... Fh

Table 73 Extended Power Conditions Subcommands

Power Condition ID
00h
01h
02h...80h
81h
82h
83h
84h ... FEh
FFh

Table 74 Power Condition IDs

9.19.1 Power Conditions
dle_a, dle_b and idle_c are power conditions within the PM1:Idle power management state. standby_y and
i i
standby_z are power conditions within the PM2:Standby power management state. Please refer to ACS -2 "3.1
Definitions and abbreviations" about PM1:Idle and PM2:Standby. The power conditions are ordered from highest
power consumption (i.e., shortest recovery time) to lowest power consumption (i.e., longest recovery time) as
follows:
idle_a power >= idle_b power >= idle_c power >= standby_y power >= standby_z power
Each of these power conditions has a set of current, saved and default settings. Default settings are not modifiable.
Default and saved settings persist across power cycles. The current settings do not persist across power cycles.
Description
Restore Power Condition Settings
Go To Power Condition
Set Power Condition Timer
Set Power Condition State
Enable the EPC feature
Disable the EPC feature
Reserved
Power Condition Name
standby_z
standby_y
idle_a
idle_b
idle_c
All
Western Digital Hard Disk Drive OEM Specification
Description
Standby
Low RPM Idle
Reserved
Active Idle
Low Power Idle
Low RPM Idle
Reserved
All supported EPC power conditions
93