(b) It may be important to reduce energy used by an embedded system. (i) Explain the way energy is used when the CPU runs. (ii) Describe two techniques available in the KL25Z to reduce energy use while still running the CPU. (iii) A micro-controller, such as the KL25Z, includes a UART for serial communication. Explain how the UART can be used when the CPU is halted (i.e. in wait or sleep mode)