I'm using an ADV7391 set up to use square pixel mode and I'm seeing a glitch at the end of line three. The glitch only occurs on odd fields and occurs regularly (but not on every odd field)at the end of line three. The data being driven at the input is the same for every frame.
What could be causing this glitch? The pattern can be effected (but not removed) by changing the PLL on/off and changing the DAC1 output from CVBS to Y. The frequency of the oscillations in this glitch are close to the subcarrier frequency (~3.6-3.9MHz). I am using timing mode 1 - slave.
The glitch looks like this:
Zoomed in view:
(the displayed vertical units are off by a factor of 10, the units are actually 100mV/division)
The current setup that I am using is as follows: