Instrumentation and Processor in Loop Verification for Dynamic Skip Fire Technology

Amid various cylinder deactivation technologies in automobile engines which provide better fuel efficiency, Dynamic Skip Fire (DSF) has proved to be promising. In DSF, a firing decision is made before every cylinder firing opportunity based on the engine torque requested. Providing this technology to automakers in form of a software object integratable with the customer’s engine controller is done by careful specification of interfaces and execution context definitions. The timing and performance of the software objects integrated with controller firmware can be dependent on the platform and compiler development environment used by the customer. This paper discusses the development of a code test environment for producing high-confidence verification. To do so an industry-accepted verification tool suite is used. Execution timing data of various functions of the source code is analyzed in detail, as well as input-output correctness. Critical software issues are readily identified before delivery to the customer. A method for determining the computational time required for the software modules is shown, and advantages of this method are discussed. Further advantages of this procedure for testing and calibration are described.