Texas Instruments TVP5147M1PFP - Manual (Page 64)

Functional Description
56 SLES140A—March 2007 TVP5147M1PFP
2.11.53 AGC White Peak Processing Register
Subaddress 74h
Default 00h
7 6 5 4 3 2 1 0
Luma peak A Reserved Color burst A Sync height A Luma peak B Composite peak Color burst B Sync height B
Luma peak A: Use of the luma peak as a video amplitude reference for the back-end feed-forward type AGC
algorithm.
0 = Enabled (default)
1 = Disabled
Color burst A: Use of the color burst amplitude as a video amplitude reference for the back end.
NOTE: Not available for SECAM, component, and B/W video sources.
0 = Enabled (default)
1 = Disabled
Sync height A: Use of the sync height as a video amplitude reference for the back-end feed-forward type AGC
algorithm.
0 = Enabled (default)
1 = Disabled
Luma peak B: Use of the luma peak as a video amplitude reference for the front-end feedback type AGC
algorithm.
0 = Enabled (default)
1 = Disabled
Composite peak: Use of the composite peak as a video amplitude reference for the front-end feedback type
AGC algorithm.
NOTE: Required for CVBS video sources.
0 = Enabled (default)
1 = Disabled
Color burst B: Use of the color burst amplitude as a video amplitude reference for the front-end feedback type
AGC algorithm.
NOTE: Not available for SECAM, component, and B/W video sources.
0 = Enabled (default)
1 = Disabled
Sync height B:
Use of the sync height as a video amplitude reference for the front-end feedback type AGC algorithm.
0 = Enabled (default)
1 = Disabled
NOTE: If all 4 bits of the lower nibble are set to logic 1 (that is, no amplitude reference selected),
then the front-end analog and digital gains are automatically set to nominal values of 2 and
2304, respectively.
If all 4 bits of the upper nibble are set to logic 1 (that is, no amplitude reference selected), then
the back-end gain is set automatically to unity.
If the input sync height is greater than 100% and the AGC-adjusted output video amplitude becomes less than
100%, then the back-end scale factor attempts to increase the contrast in the back end to restore the video
amplitude to 100%.