AMD Geode LX 800@0.9W - Manual (Page 449)

AMD Geode™ LX Processors Data Book 449
Video Processor Register Descriptions 33234H
6.8.3.38 Even Video Y Position (VYE)
6.8.3.39 Even Alpha Window 1 Y Position (A1YE)
VP Memory Offset 138h
Type
R/W
Reset Value 00000000_00000000h
VYE 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
VYE 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 140h
Type
R/W
Reset Value 00000000_00000000h
A1YE 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 ALPHA1_Y_END RSVD ALPHA1_Y_START
A1YE Bit Descriptions
Bit Name Description
63:27 RSVD (RO) Reserved (Read Only). Reads back as 0.
26:16 ALPHA1_Y_
END Alpha Window 1 Y End. Indicates the vertical end position of alpha window 1. 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 ALPHA1_Y_
START Alpha Window 1 Y Start. Indicates the vertical start position of alpha window 1. 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 values programmed in the Display Controller module registers. The value of
(V_TOTAL – V_SYNC_END) is sometimes referred to as “vertical back porch”.