Here is another example where peripherals can be employed instead of using the CPU to accomplish certain functions. In this example, a PWM output is generated from the MCU. On the left is a 100% CPU load, software-only example. In this case, an output pin is set, a delay is called, the output pin is cleared, and a second delay is called. Again, this fully loads the CPU simply to create a PWM waveform. Many MCUs employ PWM timers that can do this function automatically, and the MSP430 is no different. The example on the right shows the setup required for the MSP430 PWM timer. Once it’s set up, it requires no further CPU loading to accomplish its PWM output. The point of the example is to show the mindset or the philosophy of using peripheral functions instead of software functions to offload the CPU. Going through the steps to create a low power system design, the more that can be accomplished without the CPU, the lower the power consumption that system will have. As such, the designer should be continually asking the questions: what can be done without the CPU; what is available in the peripheral set; what features are available; how can this specific task be performed with as little CPU intervention as possible?