Samsung S5PC100 User Manual page 1201

2D-ACCELERATOR
• Data Format
♦ Supports 16/24/32-bpp color format
♦ Supports YUV input (4:2:2, 2-planar)
♦ Supports Little/Big Endian
♦ 11.11 fixed point format for coordinate data
3 COLOR FORMAT CONVERSION
2D-ACCELERATOR supports seven color formats namely: RGB_565, RGBA_5551, ARGB_1555, RGBA_8888,
ARGB_8888, XRGB_8888, and RGBX_8888. The structure of each color format is illustrated in the figure below.
RGB _565
RGBA _5551
ARGB _1555
31
RGBA _8888
31
ARGB _8888
31
XRGB _8888
31
RGBX _8888
The internal computations use ARGB_8888 format. All data's (source, destination, foreground, background, blue-
screen, and pattern) are converted to ARGB_8888 format before computation. The results are converted to the
color format specified by DEST_COLOR_MODE_REG before writing to frame buffer.
If a 16-bit color data is converted to 32-bit, the data of each field is shifted (8 – x) bits to left, where x is the bit-
width of the field. The least significant x bits of the new field data are padded with the most significant x bits of the
original field data. For example, if the R-value in RGB_565 format is 5'b11010, it is converted to 8'b11010110,
with three LSBs padded with three MSBs (3'b110) from the original R value. Note that, the A field in RGBA_5551
and ARGB_1555 only has one bit, so it is converted to either 8'b00000000 or 8'b11111111 (A=1'b1).
If a 32-bit color data is converted to 16-bit, the data of each field is truncated to x bits, where x is the bit-width of
the field in the new color format. For example, if the R value in RGBA_8888 format is 8'b11001110, it is converted
to 5'b11001 in the RGB_565 format, with the three LSBs discarded. Note: If the A field of the 32-bit color data is
not 0, the A field in RGBA_5551 and ARGB_1555 will be 1'b1; otherwise, 1'b0.
2D-ACCELERATOR also supports YUV input (format: YUV422, 2-planar). The memory allocation of a 16-pixel
image of YUV422 format is illustrated in the figure below. Note: If YUV format is used, the source image
9.5-2
24
R
24
A
24
0xFF
24
R
15
R
15
R
15 14
A R
16
G
16
R
16
R
16
G
S5PC100 USER'S MANUAL (REV1.0)
11 5
G
11 6
G
10 5
G
8
B
8
G
8
G
8
B 0xF
0
B
1 0
B A
0
B
0
A
0
B
0
B
0
F