How is GPIO power in the NuMicro? M451 series divided?

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The GPIO power in the NuMicro? M451 series is divided into three parts:
In addition to PE.8 - PG.13 and PF.0 - PN.2, VDD provides all GPIO operating voltage. In accordance with the needs of the application, the VDD voltage range can be set as 2.5V - 5.5V.
For PE.8 - PE.13, the GPIO operating voltage is exclusively supplied by VDDIO (Voltage Adjustable Interface). In accordance with the characteristics of peripheral devices, the VDDIO voltage can be independently powered and the range can be set as 1.8V - 5.5V. Specifically, the PE.8 - PE.13 can be set as external pins of UART, SPI or I?C.
For PF.0~PF.2, the GPIO operating voltage is supplied by VBAT. The RTC operating voltage is also supplied by VBAT. In accordance with RTC power requirements, the voltage supplied from the external to VBAT must be 2.5V - 5.5V. If the application contains the RTC and VBAT external battery, PF.0 and PF.1 must be connected to a 32 kHz crystal. It is recommended to set PF.2 to high impedance input mode at this time to avoid generating output current and accelerating battery consumption.