Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Microchip Technology/ATSAME51J19A/CAN0/RXF1C#0x0
Rx FIFO 1 Configuration
Rx FIFO 1 Start Address
Rx FIFO 1 Size
Rx FIFO 1 Watermark
FIFO 1 Operation Mode
https://github.com/cmsis-svd/cmsis-svd-data