Several companies have implemented in silicon the international standardized Controller Area Network (ISO 11898). The layered data link layer provides basic communication services such as transmission of data and requesting of data. The CAN protocol also handles the detection of failures as well as the error indication. All existing implementations use the same protocol handler, which has to be compliant with the C or VHDL reference model from Bosch. The implementations differ in the acceptance filtering, the frame storage capabilities, and in additional, nice-to-have features.