ALXD800EEXJ2VD AMD (ADVANCED MICRO DEVICES), ALXD800EEXJ2VD Datasheet - Page 392

• Manufacturer Part Number: ALXD800EEXJ2VD
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of ALXD800EEXJ2VD

• Operating Temperature (min): 0C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

6.7.5
Video data is mixed with graphics data according to the
video window position. The video window position is pro-
grammable via the Video X Position (VP Memory Offset
010h) and Video Y Position (VP Memory Offset 018h) reg-
isters. A color-keying and alpha-blending mechanism is
employed to compare either the source (video) or destina-
tion (graphics) color to the color-key programmed via the
Video Color-Key register (VP Memory Offset 028h), and to
select the appropriate bits in the Video Color Mask register
(VP Memory Offset 030h). This mechanism greatly
reduces the software overhead for computing visible pix-
els, and ensures that the video display window can be par-
tially hidden by overlapping graphics data. See Figure 6-27
on page 393.
The Video Processor module accepts graphics data at the
graphics Dot clock rate. The Video Processor module can
display graphics resolutions up to 1920x1440 on CRT, at
color depths up to 24 bpp while simultaneously overlaying
a video window.
6.7.5.1
Alpha-blending can be performed using RGB blending or
YUV blending:
• For RGB blending, graphic data in RGB format and
• YUV blending eliminates video de-interlacing and YUV
Up to three alpha windows can be defined in the video win-
dow. Alpha values for blending are defined for each pixel in
the upper 8 bits of video data. If alpha windows overlap,
the alpha window with the highest priority (programmable)
is used (for the overlapped area).
Alpha-blending is performed using the following formula:
Where G is the graphic value and V is the video value of
the current pixel.
392
video data in RGB format (YUV to RGB conversion) are
blended.
to RGB conversion of video data. For YUV blending, the
graphic data is converted to YUV and blended with
video in YUV format.
alpha * G + (1 - alpha) * V
Video Overlay
Alpha-Blending
33234C
Color-Keys
A color-key mechanism is used with alpha-blending. Color-
key values are defined for a cursor color-key and for a nor-
mal color-key. The cursor color-key is compared to each
24-bit value of graphic input data. If a match is found, the
selected cursor color is displayed. Two possible cursor col-
ors can be defined. The COLOR_REG_OFFSET field (in
the Cursor Color-Key register, VP Memory Offset
0A0h[28:24]) is used to select the bit in the input graphic
stream that determines the cursor color to use. Each cur-
sor color is stored in a separate cursor color register. Fig-
ure 6-28 on page 394 illustrates the logic used to
determine how to implement the color-key and alpha-
blending logic.
AMD Geode™ LX Processors Data Book
Video Processor