Using the MC68332 TPU to Implement the J1850 Protocol

This paper describes an implementation of the J1850 protocol using the Time Processor Unit (TPU) of the Motorola MC68332 microcontroller. In particular, it describes the creation of an intelligent J1850 interface that fits onto a PCMCIA Type III PC Card. A key factor allowing this much functionality to be placed into a PC Card is the integration of the J1850 interface into the MC68332 itself, rather than relying on external ICs to provide the network interface. This paper describes the organization of the J1850 interface and shows how it can be integrated into any MC68332 design in which the TPU is available for use as a communication processor.