GX1 Datasheet, PDF (127/247 Pages) National Semiconductor (TI) – Processor Series Low Power Integrated x86 Solution

Integrated Functions (Continued)
4.4.3.1 Monochrome Patterns
Setting the pattern mode to 01b (GX_BASE+8200h[9:8] =
01b) in the GP_RASTER_MODE register selects the
monochrome patterns (see bit details on page 132). Those
pixels corresponding to a clear bit (0) in the pattern are ren-
dered using the color specified in the GP_PAT_COLOR_0
(GX_BASE+8110h) register, and those pixels correspond-
ing to a set bit (1) in the pattern are rendered using the
color specified in the GP_PAT_COLOR_1 register
(GX_BASE+8112h).
If the pattern transparency bit is set high in the
GP_RASTER_MODE register, those pixels corresponding
to a clear bit in the pattern data are not drawn.
Monochrome patterns use registers GP_PAT_DATA_0
(GX_BASE+ Memory Offset 8120h) and GP_PAT_DATA_1
(GX_BASE+ Memory Offset 8124h) for the pattern data.
Bits [7:0] of GP_PAT_DATA_0 correspond to the first row of
the pattern, and bit 7 corresponds to the leftmost pixel on
the screen. How the pattern and the registers fully relate is
illustrated in Figure 4-12.
4.4.3.2 Dither Patterns
Setting the pattern mode to 10b (GX_BASE+8200h[9:8] =
10b) in the GP_RASTER_MODE register selects the dither
patterns. Two bits of pattern data are used for each pixel,
allowing color expansion to four colors. The colors are
specified in the GP_PAT_COLOR_0 through
GP_PAT_COLOR_3 registers (Table 4-24 on page 130).
Dither patterns use all 128 bits of pattern data. Bits [15:0]
of GP_PAT_DATA_0 correspond to the first row of the pat-
tern (the lower byte contains the least significant bit of each
pixel’s pattern color and the upper byte contains the most
significant bit of each pixel’s pattern color). This is illus-
trated in Figure 4-13.
GP_PAT_DATA_0 (GPD0) = 0x441100AA
GP_PAT_DATA_1 (GPD1) = 0x115500AA
GP_PAT_DATA_2 (GPD2) = 0x441100AA
GP_PAT_DATA_3 (GPD3) = 0x115500AA
GP_PAT_DATA_0 (GPD0) = 0x80412214
GP_PAT_DATA_1 (GPD1) = 0x08142241
14
GPD0[7:0]
22
GPD0[15:8]
41
GPD0[23:16]
80
GPD0[31:24]
41
GPD1[7:0]
22
GPD1[15:8]
14
GPD1[23:16]
08
GPD1[31:24]
00 0 0 0 0 0 0 0 0
AA 1 0 1 0 1 0 1 0
00AA 01 00 01 00 01 00 ^{01 00} GPD0[15:0]
4411 00 10 00 01 00 10 00 01 GPD0[31:16]
00AA 01 00 01 00 01 00 01 00 GPD1[15:0]
1155 00 01 00 11 00 01 00 11 GPD1[31:16]
00AA 01 00 01 00 01 00 01 00 GPD2[15:0]
4411 00 10 00 01 00 10 00 01 GPD2[31:16]
00AA ^{01 00 01 00 01 00 01 00} GPD3[15:0]
1155 00 01 00 11 00 01 00 11 GPD3[31:16]
Figure 4-12. Example of Monochrome Patterns
Figure 4-13. Example of Dither Patterns
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