SPRUIL1D May 2019 – December 2024 DRA829J , DRA829J-Q1 , DRA829V , DRA829V-Q1 , TDA4VM , TDA4VM-Q1
The reference frame growing window fetches happen in the granularity of 8 lines as the height of the SDE processing block is 8. The UTC needs to be configured to bring 8 consecutive lines on every event trigger. Only after 2 DMA event triggers, a sufficient amount of data (16 lines) would have been accumulated which would trigger the SDE operation. The SL2 buffer is sized to hold a maximum 24 lines, so it must wrap around at that granularity. Although it is not quite mandatory, while setting up the destination side transfer parameters, care must be taken to achieve staggering, only if SL2 size permits. In other words, two vertically adjacent pixels should come from different SL2 banks. For example, in case the image width is 2048 pixels, this would mean 3KB of data per line. Without any staggering, two vertically adjacent pixels would fall in the same memory bank of DMPAC SL2. This can cause SL2 access problems considering SDE reference frame growing window access pattern. To avoid this situation, a dummy SL2 word (64 bytes) needs to be inserted at the end of every line. This will make vertically adjacent pixels to come from different banks. If the image width is such that staggering happens naturally, the addition of a dummy SL2 word does not need to be done.