Intel® Quartus® Prime Pro Edition User Guide: Scripting

ID 683432
Date 12/13/2021
Public

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3.1.28.15. set_active_clocks (::quartus::sdc_ext)

The following table displays information for the set_active_clocks Tcl command:

Tcl Package and Version

Belongs to ::quartus::sdc_ext

Syntax set_active_clocks [-h | -help] [-long_help] <clocks>
Arguments -h | -help Short help
-long_help Long help with examples and possible return values
<clocks> List or collection of clocks
Description

Sets the list of active clocks for timing analysis. All other clocks not in the list or collection are considered inactive. Timing analysis is only performed on active clocks. All clocks are active by default. Generated clocks that are generated from inactive clocks are considered inactive. Therefore, to make a generated clock active, specify both the parent and generated clock when calling set_active_clocks. To reset all clocks to active, call "set_active_clocks *" or "set_active_clocks [all_clocks]". The set_active_clocks command does not affect all reports. For example, inactive clocks are still reported by report_clocks, report_clock_transfers, and similar commands.

Example Usage
# Only analyze clk1
set_active_clocks [get_clocks clk1]

# Only analyze clk2
set_active_clocks [get_clocks clk2]

# Analyze all clocks
set_active_clocks [all_clocks]
Return Value Code Name Code String Return
TCL_OK 0 INFO: Operation successful
TCL_ERROR 1 ERROR: Timing netlist does not exist. Use create_timing_netlist to create a timing netlist.

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