Intel® Quartus® Prime Pro Edition User Guide: Timing Analyzer

ID 683243
Date 8/03/2023

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents Report Clocks and Clock Network

The Timing Analyzer's Reports > Clocks > Report Clocks command reports all clock signals in the design. The equivalent scripting command is report_clocks.

Report Clocks generates the Clock Summary report that lists details about all of the signals with clock setting constraints in the design.

Figure 49. Clock Summary Report Shows Properties of Clock Signals in Design

Similarly, you can click the Reports > Clocks > Report Clock Network... command to generate a custom report that helps you identify and evaluate advanced clock structures, such as clock muxes, clock gates, and clock dividers.

Figure 50. Report Clock Network Dialog Box
Table 8.  Report Clock Network Dialog Box Settings
Option Description
Report target Specifies the collection of clocks and nodes that you want to analyze and report.
Expand clock path Displays all subordinate nodes in expanded view. The default display collapses trivial nodes in the report.
Include potential clock paths Includes nodes in the report that are not on a clock path, but are upstream of a register clock port.
Report panel name Specifies the name that appears in the report panel title bar.
File name Specifies the name of an optional output file to contain report data.
Tcl command Displays the Tcl syntax that corresponds with the GUI options you select. You can copy the command from the Console into a Tcl file.

This report shows the nodes on the clock network hierarchically, starting from the input clock ports, followed by any other nodes that transform or route the clocks to the clock loads. The Join Points indicate whether the clock network has convergence, such as with clock muxes. The Statistics Table provides more details about the signals that you select in the report, such as the relationships between the incoming and outgoing clocks of this node.

Figure 51. Report Clock Network Report

Right-click any of the nodes in the Clock Network report to click Open Clock Network Viewer. The Clock Network Viewer displays a graphical representation of the clock domains and constraints on the clock network to help you to see clock tree problems, such as signals entering and exiting globals. Use this graphical view to determine which clocks drive portions of the design. The Clock Network Viewer color codes the clock connection edge to indicate the clock types.

  • Blue—the base clock
  • Orange—a derived clock
  • Green—a multicycle clock

The display shows a truncated signal name by default. Hover the mouse over the clock signals to display the full signal name. Right-click any signal to display the Color Legend. Click the Zoom controls to view more detail. You can export the schematic view as a PDF from the right-click menu.

Figure 52. Clock Network Viewer

You can also right-click and choose Report Paths from Node, Report Paths Thru Node, Report Paths To Node, or Focus On Node to rerun the report on the selected node.