[waswaswas]

One example of a precaution taken: Spread-spectrum clocking.

Perfectly clocked signals have really high EM spectral peaks (noise radiated at particular frequencies). You can intentionally make the clock a little worse, spreading that radiation over more of the spectrum, and it will reduce the chance that those peaks break other things.

https://www.microsemi.com/document-portal/doc_download/13543...