Explicit Packet Switching - 2024.1 English

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

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2024.1 English

Just as multiple AI Engine kernels can share a single processor and execute in a interleaved manner, multiple stream connections can be shared on a single physical channel. This mechanism is known as Packet Switching. The AI Engine-ML architecture and compiler work together to provide a programming model where up to 32 stream connections can share the same physical channel.

The Explicit Packet Switching feature allows fine-grain control over how packets are generated, distributed, and consumed in a graph computation. Explicit Packet Switching is typically recommended in cases where many low bandwidth streams from common PL source can be distributed to different AI Engine-ML destinations. Similarly, many low bandwidth streams from different AI Engine-ML sources to a common PL destination can also take advantage of this feature. Because a single physical channel is shared between multiple streams, you minimize the number of AI Engine-ML to PL interface streams used. This section describes graph constructs to create packet-switched streams explicitly in the graph.