Logically Exclusive Clock Groups with No Interaction - 2021.2 English

Vivado Design Suite User Guide: Using Constraints (UG903)

Document ID
UG903
Release Date
2021-11-17
Version
2021.2 English

Logically exclusive clocks are clocks that are defined on different source points but share part of their clock tree due to a multiplexer or other combinational logic. The Timing Constraints wizard identifies such clocks and recommends a clock groups constraint directly on them when they do not have timing paths between each other except for the logic connected to their shared clock tree. The following figure shows an example of two clocks, clkA and clkB, which are defined on different input ports and start overlapping on the output of a BUFGMUX.

Figure 1. Example of Logically Exclusive Clocks with No Interaction