GX1 Datasheet, PDF (132/247 Pages) National Semiconductor (TI) – Processor Series Low Power Integrated x86 Solution

Integrated Functions (Continued)
Table 4-24. Graphics Pipeline Configuration Registers (Continued)
Bit
Name
Description
GX_BASE+8144h-8147h
GP_VGA_READ Register (R/W)
Default Value = 00000000h
Note that the register at GX_BASE+8144h is located in the area designated for the graphics pipeline but is used for VGA emulation
purposes. Refer to Table 4-39 on page 166 for this register’s bit formats.
GX_BASE+8200h-8203h
GP_RASTER_MODE Register (R/W)
Default Value = 00000000h
31:13
RSVD
Reserved: Set to 0.
12
TB
Transparent BLT: When set, this bit enables transparent BLT. The source color data will be compared to a
color key and if it matches, that pixel will not be drawn. The color key value is stored in the BLT buffer as
destination data. The raster operation must be set to C6h, and the pattern registers must be all F’s for this
mode to work properly.
11
ST
Source Transparency: Enables transparency for monochrome source data. Those pixels corresponding to
clear bits in the source data are not drawn.
10
PT
Pattern Transparency: Enables transparency for monochrome pattern data. Those pixels corresponding to
clear bits in the pattern data are not drawn.
9:8
PM
Pattern Mode: Specifies the format of the pattern data.
00 = Indicates a solid pattern. The pattern data is always sourced from the GP_PAT_COLOR_0 register.
01 = Indicates a monochrome pattern. The pattern data is sourced from the GP_PAT_COLOR_0 and
GP_PAT_COLOR_1 registers.
10 = Indicates a dither pattern. All four pattern color registers are used.
11 = Indicates a color pattern. The pattern data is sourced directly from the pattern data registers.
7:0
ROP
Raster Operation: Specifies the raster operation for pattern, source, and destination data.
Note: Writing to this register launches a raster operation.
GX_BASE+8204h-8207h
GP_VECTOR_MODE Register (R/W)
Default Value = 00000000h
31:4
RSVD
Reserved: Set to 0.
3
DEST
Read Destination Data: Indicates that frame-buffer destination data is required.
2
DMIN
Minor Direction: Indicates a positive minor axis step.
1
DMAJ
Major Direction: Indicates a positive major axis step.
0
YMAJ
Major Direction: Indicates a Y major vector.
GX_BASE+8208h-820Bh
GP_BLT_MODE Register (R/W)
Default Value = 00000000h
31:9
RSVD
Reserved: Set to 0.
8
Y
Reverse Y Direction: Indicates a negative increment for the Y position. This bit is used to control the direc-
tion of screen to screen BLTs to prevent data corruption in overlapping windows.
7:6
SM
Source Mode: Specifies the format of the source data.
00 = Source is a color bitmap.
01 = Source is a monochrome bitmap (use source color expansion).
10 = Unused.
11 = Source is a text glyph (use source color expansion). This differs from a monochrome bitmap in that the
X position is adjusted by the width of the BLT and the Y position remains the same.
5
RSVD
Reserved: Set to 0.
4:2
RD
Destination Data: Specifies the destination data location.
000 = No destination data is required. The destination data into the raster operation unit is all ones.
010 = Read destination data from BLT Buffer 0.
011 = Read destination data from BLT Buffer 1.
100 = Read destination data from the frame buffer (store temporarily in BLT Buffer 0).
101 = Read destination data from the frame buffer (store temporarily in BLT Buffer 1).
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