GFX
VID1
VID2
Transparency color key
dss-074
Public Version
www.ti.com
Display Subsystem Functional Description
Figure 7-83. Video Source Transparency Example
•
Graphics destination transparency color key value:
The graphics destination transparency color key value defines the encoded pixels in the video layers to
be displayed. The encoded pixel values with the destination color key value are pixels not visible on
the screen and the pixels different from the transparency color key are displayed over the video layers.
The destination transparency color key is applicable only in the graphics region when graphics and
video overlap; otherwise, the destination transparency color key is ignored.
To enable the graphics destination transparency color key, set to 0x0 the DSS.
TCKLCDSELECTION bit for LCD output or the DSS.
[13] TCKDIGSELECTION bit for
digital output. Program the DSS.
[10] TCKLCDENABLE bit (LCD output) or the
DSS.
[12] TCKDIGENABLE bit (digital output) to enable or disable the transparency
color key.
An example is shown in
: The destination transparency is applied on graphics (GFX) layer
and the pixels without the transparency color key are displayed over the overlying layers.
1653
SWPU177N – December 2009 – Revised November 2010
Display Subsystem
Copyright © 2009–2010, Texas Instruments Incorporated