The PPI on Blackfin is the video port that handles this information. PPI stands for the parallel peripheral interface. It is a video interface, however it generally supports high speed parallel converter interfaces. In the generic sense it is a high speed parallel port and has some nice video friendly features as well. It is a pretty straightforward interface, consisting of 16 data lines, PPI15 through 0 in this picture. There are up to three frame syncs, the PPI_FS1, the_FS2, and the _FS3 and then the clock, PPI_CLK. This clock is always sourced externally to the PPI, but the frame syncs and the data, depending on the mode you’re operating in, can be either inputs or outputs. On some of the subsequent slides, in the 656 modes of operation these frame sync lines are not required because everything is embedded in the data stream.