6.1 Reset and Diagnosis
6.1.2.1 Software settings 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
6.1.2.2 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
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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.
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.