Clock and Peripheral Gating
Two habits do most of the work in a low-power design that never touches Sleep, Stop, or Standby at all the energy cost of a fixed piece of work is not simply proportional to clock speed.
Two habits do most of the work in a low-power design that never touches Sleep, Stop, or Standby at all the energy cost of a fixed piece of work is not simply proportional to clock speed.
A low-power mode is not one switch, it is a set of trade-offs arranged along a slider first the CPU clock, then every clock and the main regulator, then the regulator's own supply to everything but a small backup island.