How does the ADV202/212 synchronize to video input with HVF syncs?

ADV2x2 synchronization starts on the first active HSYNC edge after receiving the first inactive VSYNC edge.

The ADV2x2 requires HSYNC transitions on every line of active video and on blanking regions. The ADV202 and ADV212 share the same HSYNC syncing mechanism, but VSYNC synchronization on the ADV202 is different from the ADV212.

The ADV202 synchronizes to the VSYNC inactive edge only once. From then on it uses the HSYNC active edge and the dimension registers for synchronization.

For progressive video, the ADV212 synchronizes to every VSYNC inactive edge. For interlaced video, the ADV212 synchronizes to every Field1 VSYNC inactive edge.