Host Protected Area Feature; Example For Operation (In Lba Mode) - Hitachi Deskstar 7K500 Specifications

3.9 Host Protected Area Feature

Host Protected Area Feature 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 a system power
off.
The following set of commands changes the LBA/CYL, which affects the Identify Device Information:
• Read Native Max ADDRESS ('F8'h)
• Set Max ADDRESS ('F9'h)

3.9.1 Example for operation (In LBA Mode)

The following example uses hypothetical values.
Capacity (native)
Max LBA (native)
Required size for protected area
Required blocks for protected area 403,200 (062700h)
Customer usable device size
Customer usable sector count
LBA range for protected area
1. Shipping of drives from the drive manufacturer
When the drive is shipped from the manufacturer, the device has been tested to have a 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 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 the 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 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.
Deskstar 7K500 Hard Disk Drive Serial ATA Addendum
21
6,498,680,832 byte (6.4 GB)
12,692,735 (0FFFFFh)
206,438,400 (byte)
6,292,242,432 byte (6.2 GB)
12,289,536 (BB8600h)
BB8600h to C1ACFFh