AXI4-Stream Protocol Overview

Protocol Structure

The AXI4-Stream protocol is a lightweight data transfer mechanism that uses a simple handshake between the source (master) and sink (slave). Data is sent in units called bursts, which are sequences of one or more data beats. Each beat is transferred when both sides agree: the source asserts TVALID to indicate valid data, and the sink asserts TREADY to signal readiness to accept it.

Within a burst:

• TVALID stays high while the source has data to send.
• TREADY may toggle depending on whether the sink can accept data.
• A transfer occurs only when both TVALID and TREADY are high in the same cycle.

This handshake ensures flow control: the source never overruns the sink, and the sink can apply backpressure by deasserting TREADY.

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