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

ID 683819
Date 10/02/2023

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Document Table of Contents

3.1. Signal Tap Logic Analyzer Introduction

The Signal Tap logic analyzer, available in the Intel® Quartus® Prime software, captures and displays the real-time signal behavior in an Intel FPGA design. Use the Signal Tap logic analyzer to probe and debug the behavior of internal signals during normal device operation, without requiring extra I/O pins or external lab equipment.

By default, the Signal Tap logic analyzer captures data continuously from the signals you specify while the logic analyzer is running. To capture and store only specific signal data, you specify conditions that trigger the start or stop of data capture. A trigger activates when the trigger conditions are met, stopping analysis and displaying the data. You can save the captured data in device memory for later analysis, and filter data that is not relevant.

Signal Tap Logic Analyzer Instance

You enable the logic analyzer functionality by defining one or more instances of the Signal Tap logic analyzer in your project. You can define the properties of the Signal Tap instance in the Signal Tap logic analyzer GUI, or by HDL instantiation of the Signal Tap Logic Analyzer Intel® FPGA IP. After design compilation, you configure the target device with your design (including any Signal Tap instances), which enables data capture and communication with the Signal Tap logic analyzer GUI over a JTAG connection.

Figure 19.  Signal Tap Logic Analyzer Block Diagram

Signal Tap Logic Analyzer GUI

The Signal Tap logic analyzer GUI helps you to rapidly define and modify Signal Tap signal configuration and JTAG connection settings, displays the captured signals during analysis, starts and stops analysis, and displays and records signal data. When you configure a Signal Tap instance in the GUI, Signal Tap preserves the instance settings in a Signal Tap Logic Analyzer file (.stp) for reuse.

Figure 20.  Signal Tap Logic Analyzer GUI

Signal Tap Logic Analyzer and Simulator Integration

You can integrate the Signal Tap logic analyzer with your supported simulator environment. Signal Tap can readily generate a list of "simulator-aware" nodes to tap for any design hierarchy. Tapping this set of nodes then provides full visibility into the entire design hierarchy for direct observation of all internal signal states in your RTL simulator.

Signal Tap also supports automatic RTL simulation testbench creation, allowing you to export acquired Signal Tap hardware data directly into your RTL simulator and observe signals beyond those that you specify for tapping in Signal Tap. You can produce simulation events using the live data traffic to replicate in your simulator.

Signal Tap Logic Analyzer Capabilities

The Signal Tap logic analyzer supports a high number of channels, a large sample depth, fast clock speeds, and other features described in the Key Signal Tap Logic Analyzer Capabilities table.

Table 7.  Key Signal Tap Logic Analyzer Capabilities
Capability Benefit
Multiple logic analyzers in a single device, or in multiple devices in a single chain Capture data from multiple clock domains and from multiple devices at the same time.
Up to 10 trigger conditions for each analyzer instance Send complex data capture commands to the logic analyzer for greater accuracy and problem isolation.
Power-up trigger Capture signal data for triggers that occur after device programming, but before manually starting the logic analyzer.
Custom trigger HDL object Define a custom trigger in Verilog HDL or VHDL and tap specific instances of modules across the design hierarchy, without manual routing of all the necessary connections.
State-based triggering flow Organize triggering conditions to precisely define data capture.
Flexible buffer acquisition modes Precise control of data written into the acquisition buffer. Discard data samples that are not relevant to the debugging of your design.
MATLAB* integration with MEX function Collect Signal Tap capture data into a MATLAB* integer matrix.
RTL simulator integration Easily create a set of nodes to tap for the design hierarchy, and observe all internal signal states in your RTL simulator. Automatic testbench creation allows you to inject acquired Signal Tap data directly into your RTL simulator.
Up to 4,096 channels per logic analyzer instance Samples many signals and wide bus structures.
Up to 128K samples per instance Captures a large sample set for each channel.
Fast clock frequencies Synchronous sampling of data nodes using the same clock tree driving the logic under test.
Compatible with other debugging utilities Use the Signal Tap logic analyzer in tandem with any JTAG-based on-chip debugging tool, such as an In-System Memory Content editor, to change signal values in real-time.
Floating-Point Display Format
  • Single-precision floating-point format IEEE754 Single (32-bit).
  • Double-precision floating-point format IEEE754 Double (64-bit).