Device Configuration Freeze Lock (Subcommand C1H); Device Configuration Identify (Subcommand C2H); Device Configuration Set (Subcommand C3H) - IBM IC25N020ATDA04 - Travelstar 20 GB Hard Drive Specifications

13.2.2 DEVICE CONFIGURATION FREEZE LOCK
The DEVICE CONFIGURATION FREEZE LOCK command prevents accidental modification of the
Device Configuration Overlay settings. After successful execution of a DEVICE CONFIGURATION
FREEZE LOCK command, all DEVICE CONFIGURATION SET, DEVICE CONFIGURATION FREEZE
LOCK, DEVICE CONFIGURATION IDENTIFY, and DEVICE CONFIGURATION RESTORE commands
are aborted by the device. The DEVICE CONFIGURATION FREEZE LOCK condition shall be cleared by
a power-down. The DEVICE CONFIGURATION FREEZE LOCK condition shall not be cleared by
hardware or software reset.

13.2.3 DEVICE CONFIGURATION IDENTIFY (subcommand C2h)

The DEVICE CONFIGURATION IDENTIFY command returns a 512 byte data structure via PIO data-in
transfer. The content of this data structure indicates the selectable commands, modes, and feature sets
that the device is capable of supporting. If a DEVICE CONFIGURATION SET command has been issued
reducing the capabilities, the response to an IDENTIFY DEVICE or IDENTIFY PACKET DEVICE
command will reflect the reduced set of capabilities, while the DEVICE CONFIGURATION IDENTIFY
command will reflect the entire set of selectable capabilities.
The format of the Device Configuration Overlay Data structure is shown on the next page.

13.2.4 DEVICE CONFIGURATION SET (subcommand C3h)

The DEVICE CONFIGURATION SET command allows a device manufacturer or a personal computer
system manufacturer to reduce the set of optional commands, modes, or feature sets supported by a
device as indicated by a DEVICE CONFIGURATION IDENTIFY command. The
DEVICE CONFIGURATION SET command transfers an overlay that modifies some of the bits set in
words 63, 82, 83, 84, and 88 of the IDENTIFY DEVICE command response. When the bits in these
words are cleared, the device no longer supports the indicated command, mode, or feature set. If a bit is
set in the overlay transmitted by the device that is not set in the overlay received from a
DEVICE CONFIGURATION IDENTIFY command, no action is taken for that bit.
The format of the overlay transmitted by the device is described in Figure 78 on page 116. The
restrictions on changing these bits is described in the text following that table. If any of the bit
modification restrictions described are violated or any setting is changed with DEVICE
CONFIGURATION SET command, the device shall return command aborted. In that case an error
reason code is returned to the sector count register, an invalid word location is returned to cylinder high
register, and an invalid bit location is returned to the cylinder low register. The Definition of error
information is shown in Figure
ERROR INFORMATION EXAMPLE 1:
If a protected area has been established with SET MAX address and if a user attempts to change
maximum LBA address (DC SET or DC RESTORE), the device aborts that command and returns an
error reason code as below
Cylinder high : 03h
Cylinder low : 00h
Sector count : 06h
on page 117.
79
.
= word 3 is invalid
this register is not assigned in this case
= Protected area is now established
Travelstar 48GH, 30GN & 15GN hard disk drive specifications
(subcommand C1h)
115