The processor includes below voltage
monitor pins:
- VMON_VSYS (Early indication):
Connect the system voltage (main supply voltage - 3.3 V, 5 V or any other
voltage) through a resistor voltage divider. Consider implementing a
capacitor for noise filtering as described in the device-specific data
sheet.
- VMON_1P8_SOC, VMON_1P8_MCU
and VMON_3P3_SOC, VMON_3P3_MCU (Monitoring): These pins can be connected
directly to their respective 1.8 V and 3.3 V supplies. An internal resistor
divider with software control is implemented inside the processor for each
of these pins.
For more information see the System
Power Supply Monitor Design Guidelines section in the Applications,
Implementation, and Layout chapter of the device-specific data sheet