Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Microchip Technology/ATSAME70N21B/MCAN0/RXF0A#0x0
Receive FIFO 0 Acknowledge Register
Receive FIFO 0 Acknowledge Index
https://github.com/cmsis-svd/cmsis-svd-data