Adding Conditions - 2025.2 English - UG900

Vivado Design Suite User Guide: Logic Simulation (UG900)
Document ID
UG900
Release Date
2025-12-17
Version
2025.2 English

To add breakpoints based on a condition and output a diagnostic message, use the following commands:

add_condition <condition> <message>

For example, when using the Vivado IDE BFT example design, you can add a condition to stop simulation when the wbClk and reset signals are both active-High. Execute the following command at start of simulation to add a condition to print a diagnostic message and pause simulation when both reset and wbClk are equal to 1:

add_condition {reset == 1 && wbClk == 1} {puts "Reset went to high"; stop}

The added condition pauses simulation at 5 ns when the condition is met and "Reset went to high" displays on the console. The simulator waits for the next step or run command to resume the simulation.

-notrace Option

Normally, when you execute the add_condition command, the specified Tcl commands also echo to the console, log file, and journal file. The -notrace switch causes those commands to execute silently, suppressing the commands (but not their output) from appearing in those three places.

For example, if you execute the following example command:

puts 'Hello'

Normal behavior of the above command is to emit the following output in the console, log file, and journal file:

# puts ‘Hello’
Hello

When you execute -notrace switch, it produces only the following output:

Hello