Generating Traffic for Emulation - 2021.2 English

Versal ACAP AI Engine Programming Environment User Guide (UG1076)

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2021.2 English

This section describes how to provide input and capture the output from the AI Engine array in hardware and software emulation using AXI traffic generators. In the AI Engine simulator the input data stimulus was provided using the simulation platform construct.

PLIO("DataIn", adf::plio_32_bits, "data/input.txt")

For hardware and software emulation an equivalent feature exists that emulates the behavior of this PLIO and AXI4-Stream interface. Both Python and C++ APIs are provided to make this easier to use.

The primary external data interfaces for the AI Engine array are AXI4-Stream interfaces. These are known as PLIOs and allow the AI Engine to receive data, operate on the data, and send data back on a separate AXI4-Stream interface. The input interface to the AI Engine is an AXI4-Stream slave and the output is an AXI4-Stream master. To interact with these top level interfaces during hardware and software emulation complementary AXI4-Stream modules are provided. These complementary modules are referred to as the AXI traffic generators.

Note: The width of a PLIO interface is an important system level design decision. The wider the interface the more data can be sent per PL clock cycle.