JAJSKM3A november 2020 – november 2020 DS90UB633A-Q1
PRODUCTION DATA
For applications requiring multiple cameras for frame-synchronization, TI recommends using the general purpose input/output (GPIO) pins to transmit control signals to synchronize multiple cameras together. To synchronize the cameras properly, the system controller must provide a field sync output (such as a vertical or frame sync signal), and the cameras must be set to accept an auxiliary sync input. The vertical synchronize signal corresponds to the start and end of a frame and the start and end of a field. Note this form of synchronization timing relationship has a non-deterministic latency. After the control data is reconstructed from the bidirectional control channel, there is a time variation of the GPIO signals arriving at the different target devices (between the parallel links). The maximum latency (t1) of the GPIO data transmitted across the link is 32 µs.
The user must verify that the timing variations between the different links are within their system and timing specifications.
See Figure 7-1 for an example of this function.
The maximum time (t2) between the time the GPIO signal arrives at Camera A and Camera B is 23 µs.