The Clock Sources table is located in the Clocks Table view. You
can also edit the clock sources directly from the Diagram view or from the
Details view.
You can configure the availability of external clock sources (check the
checkbox) and set their frequencies. Some sources can have additional settings available when
you unfold the node.
If the external crystal or the system oscillator clock is available, check the checkbox in
the clock source row and specify the frequency.
Figure 1. External clock source configuration
Note: Some clock sources remain inactive even though the checkbox is checked. This is
because the clock sources functionality depends on other settings like power mode or
additional enable/disable setting options. You can hover the cursor on the setting to see a
tooltip with information on the element and possible limitations/options.