Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Keil/AT32F435xx_v2/CAN1/RFDTH0#0x0
Receive FIFO 0 high byte data register
Receive FIFO data byte 4
Receive FIFO data byte 5
Receive FIFO data byte 6
Receive FIFO data byte 7
https://github.com/cmsis-svd/cmsis-svd-data