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ADV7441A questions about automatic mode

Question asked by frankd on Sep 19, 2014
Latest reply on Sep 26, 2014 by mattp


Hello:

 

I am using the ADV7441A and have some questions.  The input data is DVI-D RGB, and output from the 7441 is also RGB.  We assume the CSCs should simply pass this data through (they are set in automatic mode).  It appears that the output data range is being limited, perhaps as if it were only being allowed to output data values up to 235 instead of 255.  We have found that changing CP_CSC_EN (User Map, Address 0x69, [4]) from 1 to 0 does away with this “saturation” limitation but also changes apparent system gain significantly (as if it were changing conversion requirements).  We understand that the gain control likely sits between the two CSCs selected by this bit (SWAP_ CSC_COEFF is set to 0). 

 

Perhaps this means the CSC(s) are not actually set to pass through when in automatic mode?  We also assume there is likely some interaction with other settings which we do not yet fully understand.  The bottom line is that we want to try to understand what is really going on in the 7441 in this area (and how we should be controlling it).

 

Thank you,

Frank

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