Frame sync is a method by which multiple cameras (image sensors) are commanded to start and end their frames at the same time. This is required in surround-view camera systems where the processor has limited memory to store incoming frames. If the frames are not synced, the processor is forced to temporarily store partial frames while it waits for other cameras to finish their frames. This is inefficient and easily avoided. Frame sync is a sigal received by an image sensor that is usually a positive pulse that occurs during the vertical blanking period. This can differ from camera to camera.
Maxim's GMSL products have a simple feature for passing frame sync from a processor to a remote camera over a single coaxial cable. An input (GPI) on the deserializer is mirrored as an output on the serializer (GPO) for frame sync operation. The MAX96705 and MAX96706 have this capability, as do other Maxim GMSL products designed for camera applications.