Automatically Derived Clock Example - Automatically Derived Clock Example - 2026.1 English

Automatically Derived Clock Example - Automatically Derived Clock Example - 2026.1 English - UG903

Vivado Design Suite User Guide: Using Constraints (UG903)

Document ID

UG903

Release Date

2026-07-01

Version

2026.1 English

In this example, an MMCM generates an automatically derived clock. The master clock clkin drives the MMCME2 instance clkip/mmcm0 on CLKIN.

Vivado names the auto-generated clock cpuClk and defines it at clkip/mmcm0/CLKOUT.

Figure 1. Auto Generated Clock Example

Tip: Query an auto-generated clock without its name using get_clocks -of_objects <pin|port|net>. This keeps your constraint or script independent of name changes.