Intel 815 Manuel D’Utilisation
Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0
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15.4.12. Overlay Alpha Blend Window Position/Size Registers
These registers allow for the alpha blending of a subsection of the overlay window positioning of the
overlay data relative to the graphics display or the secondary display active region. It allows pixel
accurate positioning. The Overlay Alpha Blend Window must be programmed to be either equal or
within the Overlay Window.
overlay data relative to the graphics display or the secondary display active region. It allows pixel
accurate positioning. The Overlay Alpha Blend Window must be programmed to be either equal or
within the Overlay Window.
15.4.12.1. AWINPOS—Alpha Blend Window Position Register
Memory Address Offset:
70h (R/W)
On-chip Reg. Mem Addr Offset:
30170h (RO; debug path)
Default Value:
00h
Access:
see address offset above
Size:
32 bits
31 27
26 16
15 11
10 0
Reserved
Alpha Blend Vertical top
line
Reserved Alpha
Blend
Horizontal
left pixel
Bit Description
31:27
Reserved.
26:16
Alpha Blend Vertical top line. Determines where on the display screen coordinates the overlay
display are alpha blended.
display are alpha blended.
Alpha Blend Vertical Top in lines 0 = begin at display first line
15:11
Reserved.
10:0
Alpha Blend Horizontal left pixel. Determines where on the display screen coordinates the overlay
display are alpha blended.
display are alpha blended.
Alpha Blend Horizontal Left in pixels 0 = begin at display left edge