We have an ADV7180 evaluation board fitted with an ADV7393. We're supplying it with composite video and can get a coherent stable video output from the chain. The problem arises when we try to use the SFL feature. The ADV7180 is generating data, and it is possible to see the effect on the ADV7393 output, but we can't get the output sub-carrier to lock to the input video burst. I've looked at the Pixel Port readback registers on the 7393 0x13 and 0x14. 0x14 is permanently stuck at FF and 0x13 is showing wide variations in values each time it is read. I've attached the files we are using to set up the two devices.