Check that the correct voltages are applied to their respective power pins on the chip, and that your power supply can provide the required current.
If the user would like to measure power on prototype PCBs, it is recommended that they install zero-ohm resistors plus probe points for each power rail. The user can then remove the zero-ohm resistor and measure across the probe points.
Check that power comes up in the correct sequence, per the device-specific data sheet.
The DVDD18 I/O supply must always be connected, even when the dual-voltage I/Os are supplied with 3.3 V.
RTC_CVDD may be connected to CVDD if no battery is used, even when using the 1.3 V core OPP.
Verify that the PLL0 and PLL1 supplies follow the filtering requirements shown in the device-specific data sheet. Each PLL must have its own filter in order to assure noise immunity.