Hitachi HTS542516K9SA00 Specifications page 127

Security Level Zero indicates High level, one indicates Maximum level. If the host sets High level and the
password is forgotten, then the Master Password can be used to unlock the device. If the
host sets Maximum level and the user password is forgotten, only an Security Erase
Prepare/Security Unit command can unlock the device and all data will be lost.
The text of the password - all 32 bytes are always significant.
Password
The Revision Code field is set with Master password. If Identifier is User, the Revision
Master Password
Code is not set. The Revision Code field is returned in Identify Device word 92. The valid
Revision Code
Revision Codes are 0000h to FFFDh. Default Master Password Revision Code is FFFEh.
FFFFh is reserved.
The setting of the Identifier and Security level bits interact as follows.
Identifier=User / Security level = High
The password supplied with the command will be saved as the new user password. The security
mode feature (lock function) will be enabled from the next power on. The file may then be unlocked
by either the user password or the previously set master password.
Identifier=Master / Security level = High
This combination will set a master password but will NOT enable the security mode feature (lock
function).
Identifier=User / Security level = Maximum
The password supplied with the command will be saved as the new user password. The security
mode feature (lock function) will be enabled from the next power on. The file may then be unlocked
by only the user password. The master password previously set is still stored in the file but may
NOT be used to unlock the device.
Identifier=Master / Security level = Maximum
This combination will set a master password but will NOT enable the security mode feature (lock
function).
Page 127 of 171
5K250 (SATA) OEM Specification