RX Buffer manual read
Introduce additional mode which allows reading from RX buffer via 4x8 bit reads, or 2x16 bit reads. This mode could be switched in MODE register. If this mode is active, then read from RX_DATA register will not have side-effect of moving read pointer to next position. Moving of read pointer to next position will be then realized by writing a bit to CMD register.
This is an alternative to caching solution if CTU CAN FD is to be integrated into 8/16bit systems.