In a lot of embedded systems, there's no particular need for the software to participate in power saving, even when the system is ultimately battery powered. Th

In a lot of embedded systems, there's no particular need for the software to participate in power saving, even when the system is ultimately battery powered. That's often true in automotive for example, where the device's power is often externally sequenced by an ignition or auxiliary signal. The quiescent draw is simply orders of magnitude lower than the average power draw of the electro-mechanical systems being controlled. It's also often true in aerospace. Additional power saving would have an intrinsic benefit, but adds complexity that is hard to justify most of the time.