The development of a cost effective single chip microcomputer based controller for engine management systems has given powertrain design engineers an alternative to the current electronic control mechanizations. With this design, several applications for simple, lower cost controllers can be explored.A single chip controller which supports throttle body fuel injection or simultaneous port fuel injection, electronic spark control, idle speed control. and various emission control functions is compared to an existing multi-chip controller. Architectural differences are discussed, highlighting the system design issues in lower cost single chip control systems. These design issues include memory configuration and allocation, throughput requirements and limitations, back-up fuel control strategies and software development and release lead times associated with the single chip controller.The mechanization of a single chip controller is reviewed in further detail, illustrating the flexibility and capability of such a design. A review of the features which enable the controller to support four, six or eight cylinders engines, to satisfy customer applications around the world, and to provide a solution for engine designers to meet varying emissions standard are discussed in further detail.A review of the future enhancements to the single chip controller completes the discussion. Microcomputer bus speed, input/output capability, memory amounts and configuration, as well as the application potential of 16 bit microcomputers are included.