Interface

(30) SECURITY UNLOCK (X 'F2')

This command cancels LOCKED MODE.

The host transfers the 512-byte data shown in Table 5.37 to the device. Operation of the device varies as follows depending on whether the host specifies the master password.

When the master password is selected

When the security level is LOCKED MODE is high, the password is compared with the master password already set. If the passwords are the same, LOCKED MODE is canceled. Otherwise, the Aborted Command error is returned. If the security level in LOCKED MODE is set to the maximum level, the Aborted Command error is always returned.

When the user password is selected

The password is compared with the user password already set. If the passwords are the same, LOCKED MODE is canceled. Otherwise, the Aborted Command error is returned.

If the password comparison fails, the device decrements the UNLOCK counter. The UNLOCK counter initially has a value of five. When the value of the UNLOCK counter reaches zero, this command or the SECURITY ERASE UNIT command causes the Aborted Command error until the device is turned off and then on. Issuing this command with LOCKED MODE canceled (in UNLOCK MODE) has no affect on the UNLOCK counter.

Table 5.37 Contents of security password

Word

 

Contents

 

 

 

0

 

Control word

 

 

Bit 0: Identifier

 

 

0

= Compares the user passwords.

 

 

1

= Compares the master passwords.

 

 

Bits 1 to 15: Reserved

 

 

 

1 to

16

Password (32 bytes)

 

 

 

17 to

255

Reserved

 

 

 

 

5-128

C141-E280