AMD Geode LX 800@0.9W - Manual (Page 425)

AMD Geode™ LX Processors Data Book 425
Video Processor Register Descriptions 33234H
6.8.3.4 Video Y Position (VY)
6.8.3.5 Video Scale (SCL)
VP Memory Offset 018h
Type
R/W
Reset Value 00000000_00000000h
VY Register Map
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
RSVD
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
RSVD VID_Y_END RSVD VID_Y_START
VY Bit Descriptions
Bit Name Description
63:27 RSVD (RO) Reserved (Read Only). Reads back as 0.
26:16 VID_Y_END Video Y End Position. Represents the vertical end position of the video window. This
value is calculated according to the following formula:
Value = Desired screen position + (V_TOTAL – V_SYNC_END) + 2. (Note 1)
15:11 RSVD (RO) Reserved (Read Only). Reads back as 0.
10:0 VID_Y_START Video Y Start Position. Represents the vertical start position of the video window. This
register is programmed relative to CRT Vertical sync input (not the physical screen posi-
tion). This value is calculated according to the following formula:
Value = Desired screen position + (V_TOTAL – V_SYNC_END) + 1. (Note 1)
Note 1. V_TOTAL and V_SYNC_END are the values written in the Display Controller module registers.
VP Memory Offset 020h
Type
R/W
Reset Value 00000000_00000000h
SCL Register Map
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
RSVD
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
GP GB
RSVD
SP
DHD
COED
LPS
SP
VSL
SCL Bit Descriptions
Bit Name Description
63:32 RSVD (RO) Reserved (Read Only). Reads back as 0.
31 GP (RO) GLIU Passed (Read Only). This bit set indicates the GLIU line buffer fill has been
passed by the Dot display. Screen display tearing might occur. This bit clears on read.
This bit is typically set if during vertical downscale, the 2nd line buffer fill hasn’t started
before the Dot display has started. This indicates an error in that the GLIU line buffer fill
can’t keep up with the Dot clock display rate.