When the system is OFF, limited functionality within the PS must stay ON by operating on a battery. The following features operate within the battery-powered domain PS:
- Battery-backed RAM (BBRAM) to hold key for secure configuration
- Real-time clock (RTC) including the crystal I/O
The Zynq UltraScale+ MPSoC includes only one battery-powered domain and only the functions those are implemented in the PS can be battery backed-up. The required I/O for the battery-powered domain includes the battery power pads and the I/O pads for the RTC crystal.