SC2200 NSC [National Semiconductor], SC2200 Datasheet - Page 330

• Manufacturer Part Number: SC2200
• Description: Thin Client On a Chip
• Manufacturer: NSC [National Semiconductor]

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Video Processor Module
Notes:
1)
2)
3)
Alpha window should not be placed outside of the video window.
“Graphics inside Video” is enabled via bit GFX_INS_VIDEO in the Video De-interlacing and Alpha Control register
(F4BAR0+Memory Offset 4Ch[8]).
The “Pixel Value” refers to either the Video value or the Graphics value, depending on the setting of bit COLOR_CHROMA_SEL
in the Display Configuration register (F4BAR0+Memory Offset 04h[20]).
value for this pixel
Replace the value
values and video
values using the
cursor color for
Blend graphics
alpha value for
Use selected
Use graphics
register value
with the color
this window
pixel
Yes
Yes
Yes
No
Figure 6-12. Color Key and Alpha Blending Logic
COLOR_CHROMA
value for this
Use video
alpha window
matches normal
enabled for this
graphics value
Pixel inside
Pixel outside
Color register
key matches
Cursor color
Pixel value
(Continued)
the video
pixel
_SEL = 1
color key
Start
window
window
No
No
Yes
Yes
No
No
1
3
No
Yes
value for this pixel
Use graphics
COLOR_CHROMA
330
matches normal
inside Video”
“Graphics
is enabled
Pixel value
_SEL = 1
color key
No
No
No
2
3
Yes
value for this
Yes
Yes
Use video
pixel
COLOR_CHROMA
_SEL = 1
No
Use graphics
value for this
pixel
Yes
Revision 3.0