15.2 Synchronous and Asynchronous Clocks

As the CPU and the peripherals can be clocked from different clock sources, possibly with widely different clock speeds, some peripheral accesses by the CPU needs to be synchronized between the different clock domains. In these cases the peripheral includes a SYNCBUSY status register that can be used to check if a sync operation is in progress. As the nature of the synchronization might vary between different peripherals, detailed description for each peripheral can be found in the sub-chapter “synchronization” for each peripheral where this is necessary.

In the datasheet references to synchronous clocks are referring to the CPU and bus clocks, while asynchronous clocks are clock generated by generic clocks.