Monolithic data circuit-terminating unit (DCU) for a one-wire vehicle network

This paper describes a chip designed to perform the function of a Data Circuit-Terminating Unit (DCU), which provides an interface of smart sensors, actuators and subnets into a one-wire ring-topology vehicle network called BAM2. The monolithic DCU interprets the messages of a proprietary two-frames polling-access protocol operating in 38.4Kbps. Instead of having a physical address assigned to each DCU, as usual in the realm of vehicle networks, every DCU in the BAM2 network is assigned a logical address by the Master unit, thus allowing easy exchangability and maintenance of the DCU´s as well as the reduction of cost of both production and assembling of the network. Prototypes of the chip were fabricated in 0.8µ m5V CMOS technology in an area of 8.7mm². Experimental results are presented.