GFX
VID1
VID2
Transparency color key
dss-075
Public Version
Display Subsystem Functional Description
www.ti.com
Figure 7-84. Graphics Destination Transparency Example
7.4.2.4.2.2 Alpha Mode
This section describes the features available in alpha mode.
Only the graphics source transparency color key is available The encoded graphics pixel color value is
compared to the transparency color key. The encoded pixel values with the source transparency key are
not visible and the under-layer encoded pixel values or solid background color are visible. To enable the
graphics source transparency color key, set to 0x0 the DSS.
[11] TCKLCDSELECTION bit
for LCD output or the DSS.
[13] TCKDIGSELECTION bit for digital output. Program the
[10] TCKLCDENABLE bit (LCD output) or the DSS.
[12]
TCKDIGENABLE bit (digital output) to enable or disable the transparency color key. In the case of CLUT
bit maps, the palette index is compared to the transparency color key and not the palette value pointed out
by the palette index.
7.4.2.4.3 Overlay Optimization (Only Available in Normal Mode)
The display controller can be configured to take advantage of the fact that the graphics pixels under video
window 1 are not visible when the transparency color key is not used. The optimization can be selected to
reduce the bandwidth used to fetch the pixels for graphics. The color key must be disabled. The graphics
pixels under the video window 1 are not fetched from system memory. At least the video window 1 and
the graphics window must be enabled. The following graphic formats are supported: RGB (RGB16 and
RGB24 packed and unpacked), YUV4:2:2, and BITMAP 8. The formats BITMAP 1, 2, and 4 are not
supported. The video format can be RGB (RGB16, RGB24 packed and unpacked, and YUV4:2:2 formats).
The DMA engine does not fetch the unnecessary graphics pixels to avoid extra bandwidth use. Only
visible pixels from graphics and video buffers in system memory are fetched and displayed by the display
controller.
7.4.2.5
Active/Passive Matrix Display Data Path
For active matrix display data path, the following blocks are serial and each of them can be bypassed:
•
Color phase rotation
•
Spatial/temporal dithering
•
Multiple cycle data format
For passive matrix display data path, the following blocks are serial and each of them can be bypassed:
•
Color phase rotation
1654
Display Subsystem
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated
Содержание OMAP36 Series
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Страница 692: ...692 MPU Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
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 ...