The clocking system is responsible for providing all clocks that are necessary for microcontroller operation. This is valid for all functional, test, and debug modes. It also provides clocks for external applications that can be selected from internal sources.

The clocking system is functionally divided into two major clock domains:

  • System clock domain for clocks covering central processing units, interconnect and data transfers structures, non-volatile memories, timers, debug, trace, and the core functions of the communication interfaces

  • Peripheral clock domain for the protocol related parts of the communication interfaces and analog digital converters

Each domain has a master clock which is used to derive the related sub-clocks by programmable division and clock gating. System clocks are synchronous to each other, and peripheral clocks are asynchronous to each other and to the system clocks. Selected clocks can be routed to external outputs for debug, test, and further processing.