Article ID: 000092769 Content Type: Troubleshooting Last Reviewed: 05/23/2025

What timing constraints do I need to apply to the automatically generated altera_reserved_* JTAG pins in my design?

Environment

    Intel® Quartus® Prime Design Software
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Description

Many in-system debugging tools, such as the Signal Tap Logic Analyzer, the In-System Sources and Probes, or the Nios® II debugger, use the JTAG interface in Altera® FPGAs. The Quartus® Prime Software automatically generates the altera_reserved_tck, altera_reserved_tms, altera_reserved_tdi, and altera_reserved_tdo pins for a design that uses a JTAG accessible module. Because of this, the Timing Analyzer flags these signals as unconstrained when an unconstrained path report is generated.

Resolution

You can constrain the JTAG signals by applying the SDC commands of the JTAG Signal Constraints template.

In the Quartus® Prime GUI, go to File > New > Synopsys Design Constraints File. Then, in the Text Editor, click on Insert Template and then select Timing Analyzer > SDC Cookbook > JTAG Signal Constraints.

Customize the constraints in the template as needed, where indicated. Save the new SDC file, add it to your project, and compile.

Related Products

This article applies to 3 products

Intel® Stratix® 10 FPGAs and SoC FPGAs
Intel® Arria® 10 FPGAs and SoC FPGAs
Intel® Cyclone® 10 GX FPGA

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