ADC trim register.
| RESERVED | Reserved. Read value is undefined, only zero should be written. |
| ADCOFFS | Offset trim bits for ADC operation. Initialized by the boot code. Can be overwritten by the user. |
| TRIM | written-to by boot code. Can not be overwritten by the user. These bits are locked after boot code write. |
| RESERVED | Reserved. Read value is undefined, only zero should be written. |