Stream Switch FIFO - 2024.1 English

AI Engine-ML Kernel and Graph Programming Guide (UG1603)

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2024.1 English

The AI Engine-ML has one 32-bit input AXI4-Stream interface and one 32-bit output AXI4-Stream interface. A fifo_depth() constraint specification allocates FIFOs from the stream switch (one 16-deep FIFO in each stream switch). The following is an example of a FIFO allocation on the stream switch requesting a fifo_depth(8).

Figure 1. FIFO Allocation on Stream Switch

A maximum FIFO depth of 40 words is the default threshold. To increase this limit, use the --swfifo-threshold compiler option, but any increase requires additional resources to route the design.