AMD Geode LX 800@0.9W - Manual (Page 264)

264 AMD Geode™ LX Processors Data Book
Graphics Processor Register Definitions 33234H
6.4.2.9 Pattern Color (GP_PAT_COLOR_x)
In solid pattern mode, the pattern hardware is disabled and GP_PAT_COLOR_0 is selected as the input to the raster oper-
ation.
In monochrome pattern mode, GP_PAT_COLOR_0 and GP_PAT_COLOR_1 are used for expanding the monochrome pat-
tern into color. A clear bit in the pattern is replaced with the color stored in GP_PAT_COLOR_0 and a set bit in the pattern
is replaced with the color stored in GP_PAT_COLOR_1.
In color pattern mode, these registers each hold part of the pattern according to Table 6-30.
These registers should only be written after setting the BPP/FMT and PM bits in GP_RASTER_MODE (GP Memory Offset
38h[31:28, 9:8]), since the value written may be replicated if necessary to fill the register. If the pattern is color, no replica-
tion is performed and the data is written to the registers exactly as it is received. If the pattern is monochrome, the write
data is expanded if the color depth is less than 32-bpp. Thus a write to these registers in 8-bpp monochrome pattern mode
takes the least significant data byte and replicates it in the four bytes of the register. In 16-bpp monochrome pattern mode,
the least significant two bytes are replicated in the upper half of the register. A read returns the replicated data.
GP Memory Offset 18h GP_PAT_COLOR_0
1Ch GP_PAT_COLOR_1
20h GP_PAT_COLOR_2
24h GP_PAT_COLOR_3
28h GP_PAT_COLOR_4
2Ch GP_PAT_COLOR_5
Type R/W
Reset Value 00000000h
Table 6-30. PAT_COLOR Usage for Color Patterns
Register 8-bpp Mode 16-bpp Mode 32-bpp Mode
GP_PAT_COLOR_0 Line 1, pixels 3-0 Line 0, pixels 5-4 Line 0, pixel 2
GP_PAT_COLOR_1 Line 1, pixels 7-4 Line 0, pixels 7-6 Line 0, pixel 3
GP_PAT_COLOR_2 Line 2, pixels 3-0 Line 1, pixels 1-0 Line 0, pixel 4
GP_PAT_COLOR_3 Line 2, pixels 7-4 Line 1, pixels 3-2 Line 0, pixel 5
GP_PAT_COLOR_4 Line 3, pixels 3-0 Line 1, pixels 5-4 Line 0, pixel 6
GP_PAT_COLOR_5 Line 3, pixels 7-4 Line 1, pixels 7-6 Line 0, pixel 7
GP_PAT_COLOR_x Register Map
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
PAT_COLOR_x
GP_PAT_COLOR_x Bit Descriptions
Bit Name Description
31:0 PAT_COLOR_x Pattern Color x.
Mono pattern mode: Pattern color for expansion.
Color pattern mode: Color pattern.