Set Max Security Extension Commands; Figure 68. Set Max Set Password Data Content - IBM IC25N040ATCS04 - Travelstar 40 GB Hard Drive Specifications

Write information data such as BIOS code within the protected area.
Change maximum LBA using Set Max ADDRESS command to 0FBFFFh with nonvolatile option.
From this point, the protected area cannot be accessed until next Set Max ADDRESS command is
issued. Any BIOS, device driver, or application software accesses the drive as if it is a 528 MB de-
vice because the device behaves like a 528 MB device.
3. Conventional usage without system software support:
Since the drive works as a 528 MB device, there is no special care required for normal use of this
device.
4. Advanced usage using protected area.
The data in the protected area is accessed by the following steps.
1. Issue Read Native Max ADDRESS command to get the real device max LBA/CYL. Returned
value shows that native device Max LBA is 0FFFFFh regardless of the current setting.
2. Make entire device accessible, including the protected area, by setting device Max LBA as
0FFFFFh via Set Max ADDRESS command with the volatile option. By using this option,
unexpected power removal or reset will prevent the protected area from remaining accessible.
3. Read information data from protected area.
4. Issue hard reset or POR to inhibit any access to the protected area.

11.10.2 Set Max security extension commands

The Set Max SET PASSWORD command allows the host to define the password to be used during the
current power on cycle. This password is not related to the password used for the Security Mode Feature
set. When the password is set, the device is in the Set Max Unlocked mode.
This command requests a transfer of a single sector of data from the host. The following figure defines the
content of this sector of information. The password is retained by the device until the next power cycle.
When the device accepts this command, the device is in Set Max Unlocked mode.
Word
0
1–16
17–255

Figure 68. Set Max SET PASSWORD data content

The Set Max LOCK command allows the host to disable the Set Max commands (except Set Max
UNLOCK and Set Max FREEZE LOCK) until the next power cycle or the issuance and acceptance of the
Set Max UNLOCK command. When this command is accepted, the device is in the Set Max Locked
mode.
The Set Max UNLOCK command changes the device from the Set Max Locked mode to the Set Max
Unlocked mode.
This command requests a transfer of a single sector of data from the host. The figure shown above
defines the content of this sector of information. The password supplied in the sector of data transferred is
compared with the stored Set Max password. If the password compare fails, then the device returns
command aborted and decrements the unlock counter. On the acceptance of the Set Max LOCK
command, this counter is set to a value of five and is decremented for each password mismatch when Set
Content
Reserved
Password (32 bytes)
Reserved
Travelstar 60GH & 40GN hard disk drive specifications
93