For DMA FIFO depth visualization, in Vitis Analyzer, select the Graph view, and select the DMA FIFO in the view.
Tip: Hover the mouse on the DMA FIFO to show
information about the DMA FIFO, such as the FIFO depth in words.
The following figure shows an example of DMA FIFO in Graph view:
Figure 1. DMA FIFO in the Graph View
The selected DMA FIFO in the Graph view is also highlighted in the Trace view. Click Trace to switch to the Trace view.
The DMA FIFO size in words is shown in the timeline, as shown in the following
figure. In the Events view,
the size information for the DMA_FIFO_SIZE event is
shown.
Figure 2. DMA FIFO in the Trace View
Note: The DMA FIFO size is shown as multiples of four,
because it only increments after it successfully writes four words (128 bits) in
a memory bank at a time. If the last words is less than four, the last words is
in held inside the S2MM channel, and is never read by the consumer. To make sure
that no data is held inside the S2MM channel, the stream must be either
continuous or a multiple of four words.
The DMA FIFO information can be used together with other design analyzing techniques to help with design optimization. For additional design analysis techniques, see AI Engine Stall Analysis in Vitis Analyzer.