Electronic engine controller with automatic hardware initiated a/d

Abstract

An electronic engine controller includes a central processing unit (CPU) which controls the operations of the controller and an analog-to-digital (A/D)converter chip which receives analog signals generated by sensors which transmit signals indicative of vehicle and engine operating parameters. The A/D converter chip automatically performs a conversion on certain signals indicative of critical engine operating parameters to generate corresponding digital values upon each engine revolution. These digital values are stored for retrieval by the CPU. Digital values corresponding to other signals are generated and transmitted upon request by the CPU. The A/D converter chip and the CPU are coupled by a serial link which operates under one of several protocols to transmit digital values from the A/D converter chip to the CPU.