Hitachi C4K60 Specifications - Page 95

7.5.33. Security Unlock [F2h] Task File Registers Command LBA High LBA Mid LBA Low Device/Head Sector Count Features 7 6 5 4 3 2 1 0 F2h XX XX XX X X X DRV X X X X XX XX The SECURITY UNLOCK command requests a transfer of a single sector of data from the host. The following table defines the content of this sector of information. Table 7.24 Password Data Format Word Contents 0 Control Word bit 15-1 Reserved bit 0 Identifier 0 = Compare user password, 1 = Compare master password 1-16 Password(32bytes) 17-255 Reserved If the Identifier bit is set to master and the device is in high security level, then the password supplied is compared with the stored master password. If the device is in maximum security level, then the SECURITY UNLOCK command is rejected. If the Identifier bit is set to user, then the device 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 counter. This counter is initially set to five and is decrement for each password mismatch when SECURITY UNLOCK command is issued and the device is locked. When this counter reaches zero then SECURITY UNLOCK and SECURITY ERASE UNIT commands are aborted until a power-on reset or a hard reset. SECURITY UNLOCK command issued when the device is unlocked have no effect on the unlock counter. The device returns aborted command error if the device is in Frozen mode. K6610170 Rev.2 Dec 22, 2004 - 95 -