Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/NXP Semiconductors/LPC11E6x/ADC/TRM#0x0
VRANGE=HIGH_VOLTAGE
ADC trim register.
Reserved.
0 (HIGH_VOLTAGE): High voltage. VDDA = 2.7 V to 3.6 V.
1 (LOW_VOLTAGE): Low voltage. VDDA = 1.8 V to 2.7 V.
https://github.com/cmsis-svd/cmsis-svd-data