A sophisticated technique covered in the guide is . This is particularly useful for latch-based designs or paths with multiple clock cycles. Normalized slack is calculated as:
Clock Tree Synthesis (CTS) is run to build dedicated, balanced buffer trees for both clocks and high-fanout signals to minimize skew and insertion delay. 6. Common Pitfalls and Troubleshooting synopsys timing constraints and optimization user guide 2021
For those working on timing closure or constraint generation, I highly recommend keeping a copy of the nearby. A sophisticated technique covered in the guide is
: When the standard single-cycle timing model is too restrictive, exceptions are used: Declaring false paths prevents the optimization engine from
A false path is a path that physically exists in the netlist but cannot exercise a toggle, or a path that does not need to be timed. Declaring false paths prevents the optimization engine from wasting computation time fixing non-existent timing issues.
: Data crossing between unrelated clock domains should be handled via hardware synchronizers and isolated with false paths.
A well-constrained design increases the robustness and reliability of the final, physical chip.