Hitachi travelstar hds723020bla642 用户手册

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页码 173
7K200 SATA OEM Specification 
58/173 
entered after power on, otherwise it is entered by a security unlock or a 
security erase unit command. 
Device Frozen mode 
The device enables all commands except those which can update the device 
lock function, set/change password. The device enters this mode via a 
Security Freeze Lock command. It cannot quit this mode until power off. 
12.9.2 
Security Level   
Following security levels are provided.   
High level security 
When the device lock function is enabled and the User Password is 
forgotten the device can be unlocked via a Master Password. 
Maximum level security 
When the device lock function is enabled and the User Password is 
forgotten then only the Master Password with a Security Erase Unit 
command can unlock the device. Then user data is erased. 
12.9.3 
Password  
This function can have 2 types of passwords as described below.   
Master Password 
When the Master Password is set, the device does NOT enable the Device 
Lock Function, and the device can NOT be locked with the Master 
Password, but the Master Password can be used for unlocking the device 
locked. 
User Password 
The User Password should be given or changed by a system user. When the 
User Password is set, the device enables the Device Lock Function, and 
then the device is locked on next power on reset. If Software Setting 
Preservation is disabled, the device is locked on COMRESET as well. 
The system manufacturer/dealer who intends to enable the device lock function for the end users, 
must set the master password even if only single level password protection is required. Otherwise, if 
the User Password is forgotten then no one can unlock the device which is locked with the User 
Password.  
12.9.4 
Master Password Revision Code   
This Master Password Revision Code is set by Security Set Password command with the master 
password. And this revision code field is returned in the Identify Device command word 92. The valid 
revision codes are 0001h to FFFEh. The default value of Master Password Revision Code is FFFEh.   
Value 0000h and FFFFh is reserved.   
12.9.5 
Operation example   
12.9.5.1  Master Password setting   
The system manufacturer/dealer can set a initial Master Password using the Security Set Password 
command, without enabling the Device Lock Function.   
12.9.5.2  User Password setting   
When a User Password is set, the device will automatically enter lock mode the next time the device 
is powered on.