Tradeoffs in Handling Unwanted J1850 Messages

A typical node on a J1850 in-vehicle computer network uses only a subset of the total message set. Discarding unwanted messages requires node resources including time, RAM, and ROM. No single message discarding scheme will simultaneously have minimum impact on all three resources. This paper investigates tradeoffs of various schemes.

For this paper, tradeoffs are determined using a Motorola 68HC11. One algorithm is very fast, but uses considerable ROM. Another algorithm uses minimal ROM, but can be extremely slow. Other presented algorithms give a range of speed verses ROM tradeoffs. RAM usage was not a significant issue.