A serial bus structure (the digital data bus) is being implemented on the 80C51, a CMOS microcomputer which will permit efficient and economical small area networks to be designed into the automobile. The system provides the designer with several new alternative solutions to design problems.
The concept of a multiple master small area network was derived by N.V. Philips Corporation and Signetics Corporation in defining the digital data bus (D2B). The D2B protocol permits arbitration between several units to gain control of the bus to satisfy the requirements of a multi-master system. The protocol permits not only the addressed device but also the controlling device (master) to be identified.
Following the description of small area networks and the D2B protocol, several possible automotive applications are discussed.