Security Unlock (F2H) - IBM DTNA-22160 - Travelstar 2.1 GB Hard Drive Specifications

12.23 Security Unlock (F2h)

C o m m a n d B l o c k O u t p u t R e g i s t e r s
R e g i s t e r
D a t a
F e a t u r e
S e c t o r C o u n t
S e c t o r N u m b e r
C y l i n d e r L o w
C y l i n d e r H i g h
D e v i c e / H e a d
C o m m a n d
E r r o r R e g i s t e r
7 6 5
B B K U N C 0 I D N
0 V 0
Figure 77. Security Unlock Command (F2h)
This command unlocks the password and cause the device to enter device unlock mode. If power on reset or
hard reset is done without executing Security Disable Password command after this command is completed,
the device will be in device lock mode. The password has not been changed yet.
The Security Unlock command requests to transfer a single sector of data from the host including informa-
tion specified in Figure 78 on page 122.
If the Identifier bit is set to master and the file is in high security mode then the password supplied will be
compared with the stored master password. If the file is in maximum security mode then the security unlock
will be rejected.
If the Identifier bit is set to user then the file compares the supplied password with the stored user password.
If the password compare fails then the device returns an abort error to the host and decrements the unlock
attempt counter. This counter is initially set to 5 and is decremented for each password mismatch. When
this counter reaches zero then all password protected commands are rejected until a hard reset or a power
off.
7 6 5 4 3 2 1 0
1 1 D
1 1 1 1 0 0 1 0
4 3 2 1 0
0 A B T T 0 N A M N
0 0 V 0 0
C o m m a n d B l o c k I n p u t R e g i s t e r s
R e g i s t e r 7 6 5 4 3 2 1 0
D a t a
E r r o r . . . S e e B e l o w . . .
S e c t o r C o u n t
S e c t o r N u m b e r
C y l i n d e r L o w
C y l i n d e r H i g h
D e v i c e / H e a d
S t a t u s . . . S e e B e l o w . . .
S t a t u s R e g i s t e r
7 6 5 4 3
B S Y R D Y D F D S C D R Q C O R I D X E R R
0 V 0
Command Descriptions
2 1 0
0 V
121