Peripheral units can consume much power even when they are not actively in use. If you are designing for low power, it is important that you disable the peripheral units and not just leave them unattended when they are not in use. But for different reasons, a peripheral unit can be left with its power supply on—it can be a careful and correct design decision, or it can be an inadequate design or just a mistake. If not the first case, then more power than expected will be consumed by your application. This will be easily revealed by the Power graph in the Timeline window. Double-clicking in the Timeline window where the power consumption is unexpectedly high will take you to the corresponding source code and disassembly code. In many cases, it is enough to disable the peripheral unit when it is inactive, for example by turning off its clock which in most cases will shut down its power consumption completely.

However, there are some cases where clock gating will not be enough. Analog peripherals like converters or comparators can consume a substantial amount of power even when the clock is turned off. The Timeline window will reveal that turning off the clock was not enough and that you need to turn off the peripheral completely.