AMD Geode LX 800@0.9W - Manual (Page 365)

AMD Geode™ LX Processors Data Book 365
Display Controller Register Descriptions 33234H
6.6.19.9 Vertical Total
6.6.19.10 Overflow
These are the high-order bits for several of the vertical programming values. See the descriptions of the respective vertical
registers for descriptions of these fields.
6.6.19.11 Preset Row Scan
Index 06h
Type R/W
Reset Value 00h
Vertical Total Register Bit Descriptions
Bit Name Description
7:0 V_TOTAL[7:0] Vertical Total Register Bits [7:0]. This is the low eight bits of a value that specifies the
total number of scan lines on the screen minus 2. This value includes the blanking area
and determines the vertical refresh rate. The high two bits of this value are in the Over-
flow register (Index 07h[5,1]).
Index 07h
Type R/W
Reset Value xxh
Overflow Register Bit Descriptions
Bit Name Description
7 V_SYNC_ST9 Vertical Sync Start Bit 9. See V_SYNC_ST[7:0] bit description (Index 10h[7:0]).
V_SYNC_ST8 is located at bit 2
6 V_DISP_EN_END9 Vertical Display Enable End Bit 9. See V_DISP_END[7:0] bit description (Index
12h[7:0]). V_DISP_END8 is located at bit 1
5 V_TOTAL9 Vertical Total Bit 9. See V_TOTAL[7:0] bit description (Index 06h[7:0]). V_TOTAL8
is located at bit 0.
4 LINE_COMP8 Line Compare Bit 8. See LINE_COMP[7:0] bit description (Index 18h[7:0]).
LINE_COMP9 is located at Index 09h[6].
3 V_BLANK_ST8 Vertical Blank Start Bit 8. See V_BLANK_ST[7:0] bit description (Index 15h[7:0]).
V_BLANK_ST9 is located at Index 09h[5].
2 V_SYNC_ST8 Vertical Sync Start Bit 8. See V_SYNC_ST[7:0] bit description (Index 10h[7:0]).
V_SYNC_ST9 is located at bit 7.
1 V_DISP_EN_END8 Vertical Display Enable End Bit 8. See V_DISP_END[7:0] bit description (Index
12h[7:0]). V_DISP_END9 is located at bit 6.
0 V_TOTAL8 Vertical Total Bit 8. See VTOTAL[7:0] bit description (Index 06h[7:0]). V_TOTAL9 is
located at bit 5.
Index 08h
Type R/W
Reset Value 00h
Preset Row Scan Register Bit Descriptions
Bit Name Description
7 RSVD Reserved.