TPV5150AM1 input selection

The TVP5150AM1 has 2 input pins so you can either connect CVBS to the Y channel or you can connect S-video to Y & C.

When you say you want both connected at the same time I assume you mean that either S-video or CVBS COULD be connected at any given time but you don't know which, and want the ability to automatically detect if EITHER S-video or CVBS is connected?

If so, then you can use the color lock status to help determine what is actually connected.

Your host software could assume CVBS, wait a little time, then check for sync lock (H & V). If H & V are locked then you know you have SOME signal but it could be S-video or CVBS. Next, check the color lock. If you have H & V and color lock when CVBS is selected then the source is in fact CVBS.

If on the other hand you have H & V lock but NOT color lock then you would switch to S-video mode. Then wait a little time, recheck H & V then check color lock. If you now have H & V AND color lock whilst in S-video mode then you do in fact have S-video. If you still only have H & V then it is possible that you are receiving a monochrome only signal with no color so you would then need to make a system operating mode decision whether to switch back to CVBS and repeat the process looking for a color signal or just stick with the monochrome only signal. If you decide to stick with the monochrome only signal though you will have no way to determine if the signal switches back to a color signal unless there is a complete stop in the video, which would then trigger a 'loss of signal' interrupt.

BR,

Steve