AMD Geode LX 800@0.9W - Manual (Page 368)

368 AMD Geode™ LX Processors Data Book
Display Controller Register Descriptions 33234H
6.6.19.18 Cursor Location Low
6.6.19.19 Vertical Sync Start
6.6.19.20 Vertical Sync End
Index 0Fh
Type R/W
Reset Value 00h
Cursor Location Low Register Bit Descriptions
Bit Name Description
7:0 CURS_LOW Cursor Location Register Bits [7:0]. Together with the register (CURS_HI, Index
0Eh[7:0]), this value specifies the frame buffer address where the cursor is displayed in
text mode. The cursor will appear at the character whose memory address corresponds
to this value.
Index 10h
Type R/W
Reset Value 00h
Vertical Sync Start Register Bit Descriptions
Bit Name Description
7:0 VERT_SYNC_ST Vertical Sync Start Register Bits [7:0]. This value specifies the scan line number
where the vertical sync signal will go active. This is a 10-bit value. Bits 9 and 8 are in the
Overflow register (Index 07h[7,2]).
Index 11h
Type R/W
Reset Value 00h
Vertical Sync End Register Bit Descriptions
Bit Name Description
7 WR_PROT Write-Protect Registers. This bit is used to prevent old EGA programs from writing
invalid values to the VGA horizontal timing registers. The LINE_COMP8 (Index 07h[4])
is not protected by this bit.
6 RSVD Not Implemented. (Refresh Cycle Select)
5 RSVD Not Implemented. (Enable Vertical Interrupt)
4 RSVD Not Implemented.(Clear Vertical Interrupt)
3:0 V_SYNC_END Vertical Sync End Register Bits [3:0]. This field represents the low four bits of a com-
pare value that specifies which scan line that the vertical sync signal goes inactive.