Host Protected Area Function; Example For Operation (In Lba Mode) - IBM IC35L040AVVN07-0 - 40GB IDE Deskstar 120GXP 7200RPM UATA-100 07N9682 Specifications

9.9 Host Protected Area Function

The Host Protected Area Function provides a protected area which cannot be accessed via conventional
methods. This protected area is used to contain critical system data such as BIOS or system management
information. The contents of the main memory of the entire system may also be dumped into the protected
area to resume after system power off.
The following set of commands changes the LBA/CYL, which affects the Identify Device Information:
Read Native Max Address
Set Max Address

9.9.1 Example for operation (in LBA mode)

The following is an example of possible values for LBA, size, and other device characteristics:
Capacity (native)
Maximum LBA (native)
Required size for protected area
Required blocks for protected area
Customer usable device size
Customer usable sector count
LBA range for protected area
1. Shipping of drives from the manufacturer
Prior to being shipped from the manufacturer the drive has been tested to have a usable capacity of
6.4 GB besides flagged media defects not visible by the system.
2. Preparation of drives by the system manufacturer
Special utility software is required to define the size of the protected area and to store the data in it. The
sequence is as follows:
i. Issue a Read Native Max Address command to get the real device maximum LBA. Returned value
shows that the native device maximum LBA is 12,692,735 (C1ACFFh) regardless of the current
setting.
ii. Make the entire device accessible including the protected area by setting device maximum LBA to
12,692,735 (C1ACFFh) via Set Max Address command. The option may be either nonvolatile or
volatile.
iii. Test the sectors for protected area (LBA > = 12,289,536 (BB8600h)) if required.
iv. Write information data such as BIOS code within the protected area.
v. Change maximum LBA using Set Max Address command to 12,289,535 (BB85FFh) with nonvolatile
option.
vi. From this point the protected area cannot be accessed until the next Set Max Address command is
issued. Since the device functions in the same manner as a 6.2 GB device, any BIOS, device
driver, or application software will access the drive as if it were a 6.2 GB device.
3. Conventional usage without system software support
Since the drive works as a 6.2 GB device, this device requires no special care for normal use.
('F8'h)
('F9'h)
6,498,680,832 byte (6.4 GB)
12,692,735 (C1ACFFh)
206,438,400 byte
403,200 (062700h)
6,292,242,432 byte (6.2 GB)
12,289,536 (BB8600h)
BB8600h to C1ACFFh
Deskstar 120GXP hard disk drive specifications
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