FIFOs can allow system jitter to be absorbed without the loss of data and help to emulate a real-life system such as an A to D converter. The AXI Stream FIFO maximum depth is 32K entries such that it may require multiple FIFOs in the stream depending on the application. The tlast signal must also be turned on to support the DMA channels. When multiple FIFOs are used the receive channel backpressure will cause the FIFOs to fill up from the end closest to the receive channel back towards the transmit channel.
The following system diagram illustrates a Vivado system that does not include back pressure and uses a FIFO between the transmit and receive channels of the DMA.
