SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
Figure 10-8 shows a top-level overview diagram of the CAL module.
The CAL module is composed of two possible data sources (two CSI-2 low level protocol decoders) plus a pixel data processing pipeline.
The CSI-2 LL protocol block receives data from a D-PHY receiver (CSI2 PHY, up to four data pairs), merges data from multiple lanes, detects and correct errors, extracts the virtual channel ID, detects and extracts the synchronization codes and re-formats the data into a stream understood by the CAL processing pipeline. Each PPI interface has a small FIFO to accommodate latencies to access the CAL pipeline.
The data from all sources is multiplexed with 64-bit granularity and sent to the CAL pipeline for further processing. The data pipeline forwards 64-bit wide data words as well as a 5-bit wide data qualifier + 4-bit validity qualifier + 5-bit CPORT number referred as TAG in this chapter.
The TAG is set by the data source and controls how the different stages in the processing pipeline behave. Figure 10-9 summarizes possible values for the data qualifier and the corresponding behavior of the different processing stages:
Figure 10-9 does not describe all possible configurations for the CAL pixel processing stages. Depending on the use case, each pixel processing stage (extraction, DPCM decoding/encoding, packing) can be individually configured or bypassed via a dedicated bit-field in the CAL_PIX_PROC_i register.