ID 683283
Date 9/24/2018
Public

2.7.3.1. Example Step 3—Project Lead Performs Final Timing Analysis and Sign-off

With these commands, the top-level .sdc file looks like the following example:
create_clock -name {clk} -period 3.000 -waveform { 0.000 1.500 } \
[get_ports {TOP_LEVEL_CLK}] # Include the lower-level SDC file set module_A_hierarchy "module_A:inst|"  # Note the final '|' character source <partition-specific constraint file such as ..\module_A\module_A_constraints>.sdc

When the project lead performs top-level timing analysis, the false path assignment from the lower-level module_A project expands to the following:

set_false_path -from module_A:inst|reg_in_1 -to module_A:inst|*

Adding the hierarchy path as a prefix to the SDC command makes the constraint legal in the top-level design, and ensures that the wildcard does not affect any nodes outside the partition that it was intended to target.