Classical CAN version
When PEX = 0 and FD Enabled = 0 bits are configured, device shall be conformant to "Classical CAN" config. This is not true at the momemnt. In this config, recessive FDF bit causes form error (instead in Classical CAN Config, it shall be accepted as recessive, but frame shall be still considered as CAN 2.0 received frame!)
Also, other reserved bits shall be accepted even if they are recessive!