2 vga input status register 0, 3 vga input status register 1, 4 vga feature control – AMD Geode LX [email protected] User Manual
Page 357: Vga input status register 0, Vga input status register 1, Vga feature control
AMD Geode™ LX Processors Data Book
357
Display Controller Register Descriptions
33234H
6.6.17.2 VGA Input Status Register 0
6.6.17.3 VGA Input Status Register 1
6.6.17.4 VGA Feature Control
Read Address
3C2h
Write Address
--
Type
R/W
Reset Value
00h
VGA Input Status Register 0 Bit Descriptions
Bit
Name
Description
7
RSVD
Not Implemented. (CRTC Interrupt Pending)
6:5
RSVD
Reserved.
4
RSVD
Not Implemented. (Display Sense)
3:0
RSVD
Reserved.
Read Address
3BAh or 3DAh
Write Address
--
Type
R/W
Reset Value
01h
VGA Input Status Register 1 Bit Descriptions
Bit
Name
Description
7:4
RSVD
Reserved.
3
VSYNC
Vertical SYNC. When a 1, indicates that the VSYNC signal is active.
2:1
RSVD
Reserved.
0
DISP_EN
Display Enable. Reads as a 0 when both horizontal and vertical display enable are
active. Reads as a 1 when either display enable signal is inactive.
Read Address
3CAh
Write Address
3BAh or 3DAh
Type
R/W
Reset Value
xxh
VGA Feature Control Register Bit Descriptions
Bit
Name
Description
7:0
RSVD
Reserved.