A fifo_depth() constraint specification above
40 allocates FIFOs from memory, known as DMA FIFOs. The following is an example of a
FIFO allocation for a request of fifo_depth(128) bytes
which is allocated in memory.
Figure 1. DMA FIFO Allocation
Note: TLAST drops when data goes through DMA FIFO.
Note: Write to DMA FIFO must be continuous or multiple
of 4 words (4 words = 128 bits).
You can also specify the type of FIFO allocated, whether stream switch or DMA, as well as their locations. See FIFO Location Constraints for more information.