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SPRUHI7A – December 2012 – Revised June 2016
Copyright © 2012–2016, Texas Instruments Incorporated
High-Definition Video Processing Subsystem (HDVPSS)
Fixed data:
Y
= VCOMP->reg11.cfg_dsply_alt_main_y_val
Cb
= VCOMP->reg11.cfg_dsply_alt_main_cb_val
Cr
= VCOMP->reg11.cfg_dsply_alt_main_cr_val
Aux layer Fixed data enable/disable VCOMP
→
reg3.cfg_aux_fixed_data_send
Fixed data:
Y
= VCOMP->reg12.cfg_dsply_alt_aux_y_val
Cb
= VCOMP->reg12.cfg_dsply_alt_aux_cb_val
Cr
= VCOMP->reg12.cfg_dsply_alt_aux_cr_val
1.2.12.4 Exceptions
1.2.12.4.1 Exception with Respect to Timing
The VCOMP gets data from external memory and is generally used to setup HD Main Video Window for
display operations through VENC. A VENC with a timebase generator determines the VCOMP’s output
timing requirements for when it needs to have pixel data ready. The VCOMP may not have pixel data
ready for display if the input pixels have yet to arrive. The following is one scenario which can possibly
create an issue.
In this case, the lower right quadrant of the Main layer is to be cropped and displayed on the top left
corner of the output. This situation is shown in
. When the first pixel of the output is needed,
the first pixel of the cropped region may not have entered the VCOMP yet. In this case, the configuration
does not work for the device even though it is conceptually valid.
Figure 1-164. Conditions Where Valid Configurations May Not Work in a System
