Visible to Intel only — GUID: mwh1412203468309
Ixiasoft
Visible to Intel only — GUID: mwh1412203468309
Ixiasoft
3.6.1.3. Derive Clock Uncertainty (derive_clock_uncertainty)
The Derive Clock Uncertainty (derive_clock_uncertainty) constraint applies setup and hold clock uncertainty for clock-to-clock transfers in the design. This uncertainty represents characteristics like PLL jitter, clock tree jitter, and other factors of uncertainty.
You can enable the Add clock uncertainty assignment (-add) to add clock uncertainty values from any Set Clock Uncertainty (set_clock_uncertainty) constraint. You can Overwrite existing clock uncertainty assignments (-overwrite) any set_clock_uncertainty constraints.
create_clock -period 10.0 -name fpga_sys_clk [get_ports fpga_sys_clk] \
derive_clock_uncertainty -add - overwrite
The Timing Analyzer generates an information message if you omit derive_clock_uncertainty from the .sdc file.