Analyzing Protocol Instances in the Wave Window - 2024.1 English

Vivado Design Suite User Guide: Logic Simulation (UG900)

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2024.1 English

This section describes the waveform features common to all interface types. See the following protocol-specific sections for more information about a specific interface type (AXI4 or AXI4-Stream).

Understanding Protocol Instances in the Wave Window

When you add a protocol instance to the wave window, the Vivado simulator creates a hierarchy of wave objects to represent the protocol instance. You cannot change the structure of the hierarchy. The type of AXI interface determines the hierarchy.

Tip: You might need to view the protocol instance input signals not included in the wave object hierarchy. While you cannot add the signals to the hierarchy, you can add them before or after the hierarchy.

Understanding Transaction Waveforms

Transaction waveforms differ from other types of waveforms. A transaction waveform displays periods of activity and inactivity of some aspect of the simulated design in contrast with displaying value changes of a signal over time. The following figure shows an example of a transaction waveform. A thin line indicates periods of inactivity, while the rectangles represent periods of activity which are generally called transaction bars. The example in the figure shows three transaction bars.

Figure 1. Transaction Waveform Display

As shown in the following figure, the transaction waveform displays a gray bar with the text Loading… while protocol analysis is performed on the inputs of the protocol instance. As the protocol analysis progresses, the gray bars shrink to reveal newly processed transaction data.

Figure 2. Transaction Waveforms Showing Incomplete Protocol Analysis