The following diagram illustrates the sequence diagram of a typical API call, starting with the call initiated by a PM Master (such as another PU):
The previous diagram shows four actors, where the first one represents the PM Master, i.e. either the RPU, APU, or a MicroBlaze™ processor core. The remaining 3 actors are the different software layers of the PMU.
First the PMU firmware receives the IPI interrupt. Once the interrupt has been identified as a power management related interrupt, the IPI arguments are passed to the Power Management Module. The PM controller then processes the API call. If necessary it may call the PMU ROM in order to perform power management actions, such as power on or off a power island, or a power domain.