Palette/gamma logic
0
1
Palette
or
gamma
1, 2, 4, and 8 BPP
Display controller palette/gamma boundary
R CLUT
(256 x 8 bits)
G CLUT
B CLUT
0
1
0
1
Index
/
8
/
24
/
24
RGB
/
8
/
8
/
8
/
8
/
8
(256 x 8 bits)
(256 x 8 bits)
dss-054
Public Version
www.ti.com
Display Subsystem Functional Description
Figure 7-69. Palette/Gamma Correction Architecture
7.4.2.2.2.1 Color Look-Up Table
The palette mode uses the encoded pixel values from the input graphics FIFO as pointers to index the
24-bit-wide palette: 1-BPP pixels address 2 palette entries, 2-BPP pixels address 4 palette entries, 4-BPP
pixels address 16 palette entries, and 8-BPP pixels address 256 palette entries.
When a palette entry is selected by the encoded pixel value, the content of the entry is sent to the
color/grayscale space/time base passive matrix dithering circuit, or to the color time base active matrix
dithering circuit.
In color mode, the value within the palette is made up of three 8-bit fields, one for each color component
(red, green, and blue). For color operation, an individual frame is limited to a selection of 256 colors (the
number of palette entries). The format of one of the palette values in the memory is as follows:
•
24-BPP Data Memory Organization (Little Endian or Nibble)
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
Unused
R
G
B
In monochrome mode, only one 8-bit value is present.
•
24-BPP Data Memory Organization (Little Endian or Nibble)
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
Unused
Unused
Unused
Gray
After passing through the palette, 256 gray scales and 16,777,216 colors are numbers obtained. A
redundancy introduced in the dithering logic step reduces these numbers when displaying. For passive
matrix panels, the colors are limited to 15 gray scales and 3375 colors.
•
Passive matrix technology
The palette is bypassed in 12, 16, and 24 BPP. The palette is not used.
•
Active matrix technology
1639
SWPU177N – December 2009 – Revised November 2010
Display Subsystem
Copyright © 2009–2010, Texas Instruments Incorporated
Содержание OMAP36 Series
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Страница 1084: ...1084 IVA2 2 Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1990: ...1990 2D 3D Graphics Accelerator SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2334: ...2334 Memory Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2700: ...2700 Memory Management Units SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2868: ...2868 HDQ 1 Wire SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2974: ...2974 UART IrDA CIR SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3054: ...3054 Multichannel SPI SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3462: ...3462 MMC SD SDIO Card Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3508: ...3508 General Purpose Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3584: ...3584 Initialization SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3648: ...3648 Debug and Emulation SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...