SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
Two possible sources (2 x PPI) can produce data that is sent through the shared CAL processing pipeline. The shared processing pipeline is time multiplexed at 64-bit word level. Data from the PPI interfaces cannot be stalled. It is therefore stored in a FIFO (per PPI) to compensate shared pipeline access latencies.
A fixed priority arbitration scheme is used when data is ready from multiple sources. PPI_0 source is with highest priority, after that PPI_1.
PPI FIFOs are only intended to compensate internal pipeline access latencies. It is SW responsibility to ensure that the total pixel rates are compatible with CAL capabilities.