Sata Bist (Built-In Self Test); Comreset Preservation Requirements - Hitachi HDS723020BLA642 Specifications

9.14 SATA BIST (Built-in Self Test)

The device supports the following BIST modes, and begins operations when it receives BIST Activate FIS.
F – Far End Analog Loopback.
L – Far End Retimed Loopback
T – Far End Transmit only
A – ALIGN Bypass (valid only in combination with T bit)
S – Bypass Scrambling (valid only in combination with T bit)
9.15 SATA Interface Power Management
The device supports both receiving host-initiated interface power management requests and initiating
interface power management. The device initiates interface power management when the device enters its
power saving mode whose power consumption is lower than Normal Idle mode.
9.16 Software Setting Preservation
When a device is enumerated, software will configure the device using SET FEATURES and other commands.
These software settings are often preserved across software reset but not necessarily across hardware reset.
In Parallel ATA, only commanded hardware resets can occur, thus legacy software only reprograms settings that
are cleared for the particular type of reset it has issued. In Serial ATA, COMRESET is equivalent to hard reset
and a non-commanded COMRESET may occur if there is an asynchronous loss of signal. Since COMRESET
is equivalent to hardware reset, in the case of an asynchronous loss of signal some software settings may be
lost without legacy software knowledge. In order to avoid losing important software settings without legacy
driver knowledge, the software settings preservation ensures that the value of important software settings is
maintained across a COMRESET. Software settings preservation may be enabled or disabled using SET
FEATURES with a subcommand code of 06h. If a device supports software settings preservation, the feature
shall be enabled by default.
9.16.1

COMRESET Preservation Requirements

The software settings that shall be preserved across COMRESET are listed below. The device is only required
to preserve the indicated software setting if it supports the particular feature/command the setting is associated
with.
INITIALIZE DEVICE PARAMETERS: Device settings established with the INITIALIZE DEVICE
PARAMETERS command.
Power Management Feature Set Standby Timer: The Standby timer used in the Power Management
feature set.
Read/Write Stream Error Log: The Read Stream Error Log and Write Stream Error Logs (accessed using
READ LOG EXT and WRITE LOG EXT).
Security mode state: The security mode state established by Security Mode feature set commands (refer
to section 6.13 of the ATA/6 specification). The device shall not transition to a different security mode state
based on a COMRESET. For example, the device shall not transition from the SEC5: Unlocked / not
Frozen state to state SEC4: Security enabled / Locked when a COMRESET occurs, instead the device shall
remain in the SEC5: Unlocked / not Frozen state.
SECURITY FREEZE LOCK: The Frozen mode setting established by the SECURITY FREEZE LOCK
command.
SECURITY UNLOCK: The unlock counter that is decremented as part of a failed SECURITY UNLOCK
command attempt.
Hitachi hard disk drive specifications
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