AMD Geode SC1201 - Manual (Page 320)

320 AMD Geode™ SC1200/SC1201 Processor Data Book
Video Processor Module 32579B
7.2.2 Video Block
The Video block receives video data from the VIP block or
the GX1 module’s video frame buffer. The video data is for-
matted and scaled and then sent to the Mixer/Blender. The
video data also changes clock domains while in the Video
block. It is clocked in with the GX1 module’s video clock
and it is clocked out with the GX1 module’s graphics clock.
A diagram of the Video block is shown in Figure 7-7.
7.2.2.1 Video Input Formatter
The Video Input Formatter accepts video data 8 bits at a
time in YUV 4:2:2, YUV 4:2:0, or RGB 6:5:6 format. The
GX1 module’s video clock is the source clock. The data can
be interlaced or progressive. When the data comes directly
from the VIP block it is usually interlaced. The video format
is configured via the EN_42X bit (F4BAR0+Memory Offset
00h[28] and the GV_SEL bit (F4BAR0+Memory Offset
4Ch[13]). The byte order for each format is configured in
the VID_FMT bits (F4BAR0+Offset 00h[3:2]).
RGB 5:6:5 – For this format each pixel is described as a
16-bit value:
Bits [15:11] = Red
Bits [10:5] = Green
Bits [4:0] = Blue
YUV 4:2:0 – This format is not supported by the GX1 mod-
ule. The Horizontal Downscaler in the Video block cannot
be used if the video data is in this format. In this format, 4
bytes of data are used to describe two pixels. The 4 bytes
contain two Y values one for each pixel; one U and one V
for both pixels. For each horizontal line, all the Y values are
received first. The U values are received next and the V
values are received last. For example for a horizontal line
that has 720 pixels, there are 720 bytes of Y, followed by
360 bytes of U, followed by 360 bytes of V.
YUV 4:2:2 – In this format each DWORD in the horizontal
line represent two pixels. There are two Y values and one
each U and V in a DWORD. Just as in the YUV 4:2:0 for-
mat, each U and V value describes the two pixels.
Figure 7-7. Video Block Diagram
Video Input
Formatter
4-Tap Horizontal
Downscaler
m
m+1
1
m+1
or
GX1 Direct
Video Input
Line Buffer 0
Line Buffer 1
Line Buffer 2
Formatter
4:4:4
2-Tap Vertical
Interpolating Upscaler
24 24
24
2-Tap Horizontal
Interpolating Upscaler
YUV 4:4:4/RGB 5:6:5
Video Module
8 8
(3x360x32 bit)
(4:2:2 or 4:2:0)