Modern system-on-chip designs don't really use a global clock anyway. It's more just local synchronous islands which communicate over asynchronous interfaces -

Modern system-on-chip designs don't really use a global clock anyway. It's more just local synchronous islands which communicate over asynchronous interfaces - i.e. https://en.wikipedia.org/wiki/Globally_asynchronous_locally_synchronous https://en.wikipedia.org/wiki/Globally_asynchronous_locally_...