Propagated Clocks - 2023.2 English

Vivado Design Suite User Guide: Using Constraints (UG903)

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2023.2 English

The period and waveform properties represent the ideal characteristics of a clock. When entering the FPGA and propagating through the clock tree, the clock edges are delayed and become subject to variations induced by noise and hardware behavior. These characteristics are called clock network latency and clock uncertainty.

The clock uncertainty includes:

By default, the Vivado IDE always treats clocks as non-ideal propagated clocks to provide an accurate slack value that includes clock tree insertion delay and uncertainty.