The Zynq UltraScale+ MPSoC can be partitioned into sub-systems, so that they can be managed independently by the power management framework. For example, you can define a Linux sub-system and a Real-time sub-system. The Linux sub-system might include the APU (as the PM master) and a number of peripherals (as the PM slaves). The Real-time sub-system might include the RPU and a number of other peripherals. Each sub-system can be powered up, powered down, restarted or suspended without affecting the other sub-systems. A sub-system has only one PM Master, and might include both FPD and LPD peripherals.
You can create your own sub-systems using the AMD Vivado™ PCW tool. The following figure shows the PCW screen shots of a valid configuration, which contains only an APU sub-system and no RPU sub-systems.