Power-Up In Standby Feature Set - Western Digital Ultrastar DC HC310 Specifications

9.10

Power-Up in Standby Feature Set

Power-Up In Standby feature set allows devices to be powered-up into the Standby power management state to
minimize inrush current at power-up and to allow the host to sequence the spin-up of devices.
This feature set will be enabled/disabled via the SET FEATURES command. The enabling of this feature set shall be
persistent after power cycle.
A device needs a SET FEATURES subcommand to spin-up to active state when the device has powered-up into
Standby. The device remains in Standby until the SET FEATURES subcommand is received.
If power-up into Standby is enabled, when an IDENTIFY DEVICE is received while the device is in Standby as a
result of powering up into Standby, the device shall set word 0 bit 2 to one to indicate that the response is incomplete,
then only words 0 and 2 are correctly reported.
The IDENTIFY DEVICE information indicates the states as follows:
 identify device information is complete or incomplete
 this feature set is implemented
 this feature set is enabled or disabled
 the device needs the Set Features command to spin-up into active state
9.11 Advanced Power Management Feature Set (APM)
This feature allows the host to select an advanced power management level. The advanced power management
level is a scale from the lowest power consumption setting of 01h to the maximum performance level of FEh. Device
performance may increase with increasing advanced power management levels. Device power consumption may
increase with increasing advanced power management levels. The advanced power management levels contain
discrete bands, described in the section of Set Feature command in detail. This feature set uses the following
functions:
1. A SET FEATURES subcommand to enable Advanced Power Management
2. A SET FEATURES subcommand to disable Advanced Power Management
Advanced Power Management is independent of the Standby timer setting. If both Advanced Power Management
and the Standby timer are set, the device will go to the Standby state when the timer times out or the device's
Advanced Power Management algorithm indicates that the Standby state should be entered.
The IDENTIFY DEVICE response word 83, bit 3 indicates that Advanced Power Management feature is supported if
set. Word 86, bit 3 indicates that Advanced Power Management is enabled if set. Word 91, bits 7-0 contain the
current Advanced Power Management level if Advanced Power Management is enabled.
9.12 48-bit Address Feature Set
The 48-bit Address feature set allows devices:
a) with capacities up to 281,474,976,710,655 logical sectors (i.e., up to 144,115,188,075,855,360 bytes for a
512-byte logical block device); and
b) to transfer up to 65 536 logical sectors in a single command.
The 48-bit Address feature set operates in LBA addressing only. Devices also implement commands using 28-bit
addressing, and 28-bit and 48-bit commands may be intermixed.
Support of the 48-bit Address feature set is indicated in the Identify Device response bit 10 words 83. In addition, the
maximum user LBA address accessible by 48-bit addressable commands is contained in Identify Device response
words 230 through 233.
When the 48-bit Address feature set is implemented, the native maximum address is the value returned by a Read
Native Max Address Ext command. If the native maximum address is equal to or less than 268,435,455, a Read
Native Max Address shall return the native maximum address. If the native maximum address is greater than
268,435,455, a Read Native Max Address shall return a value of 268,435,455.
Western Digital Hard Disk Drive OEM Specification
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