DDR Memory Access through GMIO - 2022.2 English

AI Engine Kernel and Graph Programming Guide (UG1079)

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2022.2 English

The main data streams from and to the AI Engine are the AI Engine to PL streaming interface and GMIO, which is used to make external memory-mapped connections to or from the global memory. The interface between PS and AI Engine can target low throughput purposes such as, configuration. The AI Engine-GMIO directly connects to the DDR memory through the AI Engine-NoC master unit (NMU).

The bandwidth of AI Engine GMIO is affected by the number of NMUs and DDR memory controllers used in the platform.

The benefits of AI Engine GMIO include that it can directly access DDR memory, and it is not only a virtual platform for AI Engine simulator, but also can work in hardware without PL kernels. For more information about the GMIO programming model, refer to the AI Engine Tools and Flows User Guide (UG1076).