On a Family of Run Length Limited, Block Decodable Codes to Prevent Payload-Induced Jitter in Controller Area Networks

Controller Area Networks (CAN) adopt bit stuffing at the physical layer, thus introducing a frame length variability that may adversely affect sensing and actuation jitter. One convenient way to mitigate this issue, for what concerns the CAN data field, is to encode the payload itself, by means of a suitable run length limited code, before transmission. In this paper, a family of these codes is defined and thoroughly analyzed from the theoretical point of view, showing that it is optimal within a set of performance and footprint-related constraints typical of a contemporary embedded system. Experimental results confirm that the proposed technique is amenable to an efficient and deterministic software-based implementation on an off-the-shelf microcontroller.