358 AMD Geodeā„¢ LX Processors Data Book
Display Controller Register Descriptions
33234H
6.6.18 VGA Sequencer Registers
The Sequencer registers are accessed by writing an index value to the Sequencer Index register (3C4h) and reading or
writing the register using the Sequencer Data register (3C5h).
6.6.18.1 VGA Sequencer Index
6.6.18.2 VGA Sequencer Data
6.6.18.3 VGA Reset
Table 6-51. VGA Sequencer Registers Summary
Index Type Register Reset Value Reference
-- R/W VGA Sequencer Index 0xh Page358
-- R/W VGA Sequencer Data xxh Page358
00h R/W VGA Reset 00h Page 358
01h R/W VGA Clocking Mode 02h Page 359
02h R/W VGA Map Mask 00h Page 359
03h R/W VGA Character Map Select xxh Page360
04h R/W VGA Memory Mode 02h Page360
Index Address 3C4h
Type R/W
Reset Value 0xh
VGA Sequencer Index Register Bit Descriptions
Bit Name Description
7:3 RSVD Reserved.
2:0 INDEX Index.
Data Address 3C5h
Type R/W
Reset Value xxh
VGA Sequencer Data Register Bit Descriptions
Bit Name Description
7:0 DATA Data.
Index 00h
Type R/W
Reset Value 00h
VGA Reset Register Bit Descriptions
Bit Name Description
7:2 RSVD Res erved.
1:0 DIS_EN Enable Display. Both these bits should be set to 1 (value = 11) to enable display of the
VGA screen image. If either of these bits are 0, the display is blanked. The VGA contin-
ues to respond to I/O and memory accesses.