CAN FD: Performance reality

Abstract

Automotive network is no more limited to slow speed interfaces which could fulfill its requirement with kbps speed. Increasing bandwidth requirement has posed challenge to designers to come-up with solutions which could help network run at desired high speed. Classic CAN (Controller Area Network) was conceptualized with the very same purpose but its limited speed (up to 1Mbps) became unable to serve the automotive network because of its increased appetite for bandwidth. That's where CAN FD (CAN with flexible data rate) took birth. CAN FD improved the classic CAN by incorporating two things: 1. Higher bit rate support 2. Larger payload support. By introducing these two features it was assumed that CAN FD could accommodate bandwidth up to 8Mbps (>> 1Mbps of Classic CAN) but is it really true? This is what this paper is going to answer. The paper talks about the impact of increasing bit rate or payload on overall CAN packet performance. It also throws some light on CAN FD performance with respect to different SOCs. It also describes how any other system level module could be utilized to check the overall performance of CAN FD.