386 AMD Geodeā„¢ LX Processors Data Book
Display Controller Register Descriptions
33234H
6.6.23.4 WriteMemoryAperture
6.6.23.5 ReadMemoryAperture
6.6.23.6 BlinkCounterCtl
This register is for simulation and test only.
CRTC Index 047h
Type R/W
Reset Value 00h
WriteMemoryAperture Register Bit Descriptions
Bit Name Description
7:0 WR_BASE WriteBase. Offset added to the graphics memory base to specify where VGA write oper-
ations start. This value provides DWORD address bits [21:14] when mapping host VGA
writes to graphics memory. This allows the VGA base address to start on any 64 KB
boundary within the 8 MB of graphics memory.
CRTC Index 048h
Type R/W
Reset Value 00h
ReadMemoryAperture Register Bit Descriptions
Bit Name Description
7:0 RD_BASE ReadBase. Offset added to the graphics memor y base to specify where VGA read oper-
ations start. This value provides DWORD address bits [21:14] when mapping host VGA
reads to graphics memory. This allows the VGA base address to start on any 64 KB
boundary within the 8 MB of graphics memory.
CRTC Index 060h
Type R/W
Reset Value 00h
BlinkCounterCtl Register Bit Descriptions
Bit Name Description
7 HLD_CNT Hold Count. When set, prevents the blink counter from incrementing with each leading
edge VSYNC.
6:5 RSVD Reserved.
4:0 BLNK_CNT Blink Count. The blink counter is loaded with this value while the Sequencer Reset reg-
ister is in the reset state.