Insert Clocking Elements Near the Top Level - 2020.2 English

UltraFast Design Methodology Guide for Xilinx FPGAs and SoCs

Document ID
UG949
Release Date
2021-02-18
Version
2020.2 English

Inserting the clocking elements towards the top level allows for easier clock sharing between modules. This sharing may result in fewer clocking resources needed, which helps in resource utilization, improved performance, and power.

Aside from the module the clocks are created in, clock paths should only drive down into modules. Any paths that go through (down from top and then back to top) can create a delta cycle problem in VHDL simulation that is difficult and time consuming to debug.