450 AMD Geode™ LX Processors Data Book
Video Processor Register Descriptions
33234H
6.8.3.40 Even Alpha Window 2 Y Position (A2YE)
6.8.3.41 Even Alpha Window 3 Y Position (A3YE)
VP Memory Offset 148h
Type R/W
Reset Value 00000000_00000000h
A2YE 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
313029282726252423222120191817161514131211109876543210
RSVD ALPHA2_Y_END RSVD ALPHA2_Y_START
A2YE Bit Descriptions
Bit Name Description
63:27 RSVD (RO) Reserved (Read Only). Reads back as 0.
26:16 ALPHA2_Y_
END
Alpha Window 2 Y End. Indicates the vertical end position of alpha window 2. 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 ALPHA2_Y_
START
Alpha Window 2 Y Start. Indicates the vertical start position of alpha window 2. 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”.
VP Memory Offset 150h
Type R/W
Reset Value 00000000_00000000h
A3YE 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
313029282726252423222120191817161514131211109876543210
RSVD ALPHA3_Y_END RSVD ALPHA3_Y_START
A3YE Bit Descriptions
Bit Name Description
63:27 RSVD (RO) Reserved (Read Only). Reads back as 0.
26:16 ALPHA3_Y_
END
Alpha Window 3 Y End. Indicates the vertical end position of alpha window 3. 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 ALPHA3_Y_
START
Alpha Window 3 Y Start. Indicates the vertical start position of alpha window 3. 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”.