Intel® Quartus® Prime Pro Edition User Guide: Debug Tools

ID 683819
Date 10/13/2021

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2.4.4. Specifying the Buffer Acquisition Mode

You can specify how Signal Tap organizes the data capture buffer to potentially reduce the amount of memory that Signal Tap requires for data acquisition.

The Signal Tap logic analyzer supports either a non-segmented (or circular) buffer and a segmented buffer.

  • Non-segmented buffer—the Signal Tap logic analyzer treats the entire memory space as a single FIFO, continuously filling the buffer until the logic analyzer reaches the trigger conditions that you specify.
  • Segmented buffer—the memory space is split into separate buffers. Each buffer acts as a separate FIFO with its own set of trigger conditions, and behaves as a non-segmented buffer. Only a single buffer is active during an acquisition. The Signal Tap logic analyzer advances to the next segment after the trigger condition or conditions for the active segment has been reached.

When using a non-segmented buffer, you can use the storage qualification feature to determine which samples are written into the acquisition buffer. Both the segmented buffers and the non-segmented buffer with the storage qualification feature help you maximize the use of the available memory space.

Figure 32. Buffer Type Comparison in the Signal Tap Logic AnalyzerThe figure illustrates the differences between the two buffer types.

Both non-segmented and segmented buffers can use a preset trigger position (Pre-Trigger, Center Trigger, Post-Trigger). Alternatively, you can define a custom trigger position using the State-Based Triggering tab, as Specify Trigger Position describes.