What is Fly-By DMA used for?

In fly-by mode DMA, the function of the RD and WE signals (for DMA only) are reversed. This allows a host to move data between an external device and the ADV202/212 with the use of a single strobe.

In encode mode with fly-by DMA, the host can use the RDFB signal (WE pin) to simultaneously read from the ADV202/212 and write to an external device like memory.

In decode mode with fly-by DMA, the host can use the WEFB signal (RD pin) to simultaneously read from the external device and write to the ADV202/212.