AMD Geode LX 600@0.7W Data Book page 266

33234H
Bit Name
31:28 BPP/FMT
27:24 RSVD
23:22 EN
21:20 OS
19:17 AS
16 CS
15:14 RSVD
13 SI
12 PI
11 ST
10 PT
9:8 PM
266
GP_RASTER_MODE Bit Descriptions
Description
Color Depth and Format.
0000: 8-bpp, 3:3:2 format.
0100: 16-bpp, 4:4:4:4 format.
0101: 16-bpp, 1:5:5:5 format.
0110: 16-bpp, 0:5:6:5 format.
1000: 32-bpp, 8:8:8:8 format.
All Others: Undefined.
Reserved. Write as read.
Alpha Enable Bits. Also used to select how to apply the specified operation.
00: Alpha disabled/ROP enabled.
01: Alpha operation applies to only the RGB values of the pixel. Output alpha is from
channel B if the OS is 01; otherwise from channel A.
10: Alpha operation applies to only the alpha of the pixel. Output RGB is from channel B
if the OS is 01; otherwise from channel A.
11: Alpha operation applies to all channels of the pixel (ARGB).
Alpha Operation Select. Determines the alpha operation to be performed if enabled.
00: a∗A.
01: (1-a)*B.
10: A + (1-a)*B.
11: a∗A + (1-a)*B.
* Channel A is added in this case only if the selected α is also from channel A.
Alpha Select. Chooses which alpha value to use for the multiplication.
000: a
A
001: a
B
010: a
R
011: Constant 1
Channel Select. Determines which data stream gets put on which channel.
0: A is source, B is destination.
1: A is destination, B is source.
Reserved. Write as read.
Source Invert. Inverts the sense of monochrome source data.
Pattern Invert. Inverts the sense of monochrome pattern data.
Source Transparency. Enables transparency for monochrome source data and color
keying for color source data.
0: Disable.
1: Enable.
Pattern Transparency. Enables transparency for monochrome pattern data.
0: Disable.
1: Enable.
Pattern Mode. Specifies the format of the pattern data.
00: Solid pattern. Pattern data always sourced from GP_PAT_COLOR_0 (GP Memory
Offset 18h).
01: Mono pattern.
10: Color pattern.
11: Undefined.
Graphics Processor Register Definitions
100: Color
A
101: Color
B
110: a
R
111: Constant 1
AMD Geode™ LX Processors Data Book