K6602705
Rev.3
08.20.01
- 91 -
6.3.2.11.4 Device Configuration Set [B1h, Sub 03h]
Task File Registers
7
6
5
4
3
2
1
0
Command
B1h
Cylinder High
XX
Cylinder Low
XX
Device/Head
-
X
-
DRV
XX
Sector Number
XX
Sector Count
XX
Features
03h
DRV : Device selection bit
0 : DRV0
1:DRV1
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 the IDENTIFY DEVICE command
response. When the bits in these words are cleared, the device no longer support 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 table 6.19.
Table 6.19 Device Configuration Set Command Data Structure
Word
Description
0
Data Structure Revision
Word 0 shall contain the value 0001h.
1
Multiword DMA modes supported
bit 15 - 3 0 = Reserved
bit 2
1 = Multiword DMA mode 2
and below are supported
Bit 2 is cleared to select no support for Multiword DMA mode 2. This bit shall
not be cleared if Multiword DMA mode 2 is currently selected.
bit 1
1 = Multiword DMA mode 1
and below are supported
Bit 1 is cleared to select no support for Multiword DMA mode 1. This bit shall
not be cleared if Multiword DMA mode 2 is supported or Multiword DMA mode
1 or 2 is selected.
bit 0
1 = Multiword DMA mode 0 is
supported
Bit 0 shall not be cleared.