Samsung M9T manual Security Unlock F2h, Seek 7xh, Set Features EFh

	Table 8-10 Identifier and security level bit interaction
Identifier	Level	Command result
User	High	The password supplied with the command shall be saved as the
		new User password. The Lock mode shall be enabled		from the
		next power-on or hardware reset. The device shall then be		unlocked
		by either the User password or the previously set Master password.
User	Medium	The password supplied with the command shall be saved as the
		new User password. The	Lock mode shall be enabled	from the
		next power-on or hardware	reset. The device shall then be	unlocked
		by only the User password. The Master password previously set is
		still stored in the device but shall not be used to unlock the device.
Master	High or	Maximum This combination shall set a Master password but shall
	Medium	not enable or disable the Lock mode. The security level is not
		changed. Master password revision code set to the value in Master
		Password Revision Code field.

8.2.27 Security Unlock (F2h)

This command transfers 512 bytes of data from the host. If the Identifier bit is set to Master and the device is in high security level, then the password supplied shall be compared with the stored Master password. If the device is in maximum security level then the unlock shall be rejected.

If the Identifier bit is set to the user then the device needs to compare the supplied password with the stored User password.

If the password compare fails then the device shall return command aborted to the host and decrements the unlock counter. This counter shall be initially set to five and shall be decremented for each password mismatch when SECURITY UNLOCK is issued and the device is locked. When this counter reaches zero then SECURITY UNLOCK and SECURITY ERASE UNIT commands shall be command aborted until a power-on reset or a hardware reset. SECURITY UNLOCK commands issued when the device is unlocked have no effect on the unlock counter.

8.2.28 Seek (7xh)

This command has become obsolete in the ATA7 specification. The supporting of this command is just for backward compatibility purpose.

8.2.29 Set Features (EFh)

This command is used by the host to establish the following parameters, which affect the execution of certain drive features as shown below.

Spinpoint M9T Product Manual REV 1.0 60