API Calls and Responses - 2020.2 English

Zynq UltraScale+ MPSoC Software Developer Guide (UG1137)

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2020.2 English

Power Management Communication using IPIs

In the Zynq UltraScale+ MPSoC, the power management communication layer is implemented using inter-processor interrupts (IPIs), provided by the IPI block. See this link to the “Interrupts” chapter of the Zynq UltraScale+ Device Technical Reference Manual (UG1085) for more details on IPIs.

Each PU has a dedicated IPI channel with the power management controller, consisting of an interrupt and a payload buffer. The buffer passes the API ID and up to five arguments. The IPI interrupt to the target triggers the processing of the API, as follows:

  • When calling an API function, a PU generates an IPI to the power management unit (PMU), prompting the execution of necessary power management action.
  • The PMU performs each PM action atomically, meaning that the action cannot be interrupted.
  • To support PM callbacks, which are used for notifications from the PMU to a PU, each PU implements handling of these callback IPIs.