We are using the ADV7403 in the PAL mode (SDP). Some days ago I saw a strange problem - when I try to switch between two video channels, sometimes the IC is unable to lock the video and I see complete garbage on the screen (mostly white lines and dots). Every time we switch a channel we do a reset (using the IC reset pin) and complete I2C reprogramming (even writing the default registers). After this initialization sometimes I see the described problem, so it looks like a problem related to initialization. The frequency of the problem - every 15-20 switches it will happen. Increasing the reset time doesnt help - currently it is 14msec. Reducing the I2C speed also doesn't help - currently it is 60kHz. The script itself is based on Analog Devices example script with a few modifications to Vsync and Hsync duration and the schematics is also based on the ADI eval kit schematics.
We use this exact board for RGsB (CP) video without any problems.
Any help will be greatly appreciated.