For some reason the forum is forcing me to post in Consumer & Computing Forum instead of Legacy Video Converters, but the instructions say to post anyway.
I'm running into a weird issue where sometimes after configuring the TVP5146M2, it seems to get stuck on an incorrect sync with an NTSC camera. What happens is the output picture just looks like a bunch of rapidly moving black and white horizontal blobs, and register 0x3A (Status 1) reads back as 0x14. That means vertical sync lock = true but horizontal sync lock = false and color subcarrier lock = false. It doesn't seem to be able to recover from this situation on its own. It's like it has mistakenly locked onto something that it shouldn't have locked on for vertical sync, and it's stuck.
In the code I can detect this situation and temporarily set the video standard to SECAM (write 6 to register 0x02) and then back to autoswitch (write 0 to register 0x02), which fixes the problem.
Here is my initialization sequence for the TVP5146M2 (address, value pairs):
Any ideas about what might be causing this? It's not a huge deal because I can detect and fix the situation at runtime, but it feels like the chip shouldn't be getting into that state in the first place.