The SAM S70/E70 devices have three software-selectable low-power modes. In backup mode, RTT, RTC and wake-up logic are running, and optionally a 1KB low power SRAM can be retained. Additionally, in wait mode, all clocks and functions are stopped but some peripherals can be configured to wake up the system based on predefined conditions. This feature, called SleepWalking, performs a partial asynchronous wake-up, thus allowing the processor to wake up only when needed. Finally, in sleep mode, the processor is stopped while all other functions can be kept running. To optimize power consumption in active mode, the clock system has been designed to support different clock frequencies for selected peripherals. Moreover, the processor and bus clock frequency can be modified without affecting processing on for example, the USB, USART, AFE and Timer/Counter.