We are using ADV7842 in one of our designs and I cannot find a way to process 1680x1050 HDMI/DVI input. Is it possible to use non-std resolutions with HDMI or are we stuck with the ones like 720p, 1080p, etc. ?
As long as the TMDS clock does not exceed the 225MHz limit and the LLC does not exceed the 170MHz limit the ADV7842 can process custom formats. I would start with a script close to the LLC clock you are planning on.
In addition to GuenterL comments, you would need to know the correct video input timing given below:
Horizontal Total lines
Vertical Total lines
Once the above determined, you then configure the part as follows:
PRIM_MODE[5:0] set to graphics
VID_STD[3:0] set to auto graphics
set CP_LCOUNT_MAX = Vertical Total lines
set INTERLACED bit to '0'
set the manual PLL divider ratio = Horizontal Total lines
Enable manual PLL
Calculate the Free run line length = XTAL Clock in this case is 28.636363 MHz divided by Fhsync
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