【德国博世】CAN FD原版介绍材料.pdf

CAN with Flexible Data-Rate Specification Version 1.0 (released April 17th, 2012) FD April 2012 page 1 Recital The acceptance and introduction of serial communication to more and more applica- tions has led to increasing demand for bandwidth in CAN communication and caused system developers to look for alternative communication options in certain applications. These applications can be realized more comfortably with the new protocol CAN FD that allows data rates higher than 1 MBit/s and payloads longer 8 bytes per frame. CAN FD shares the physical layer, with the CAN protocol as defined in the BOSCH CAN Specification 2.0. The frame format however, is different. There are two new con- trol bits in the CAN FD frame, the first enabling the new frame format with different data length coding and the second optionally switching to a faster bit rate after the arbitration is decided. New CRC polynomials are introduced to secure the longer CAN FD frames with the same Hamming distance as in the proven CAN protocol. The CAN FD frame format has been defined so that messages in CAN frame format and in CAN FD frame format can coexist within the same network. The BOSCH CAN Specification 2.0 remains valid without any modification as an independent, self-con- tained CAN bus protocol specification. The coexistence is assured by the requirement, that in order to be compatible with this CAN FD specification it is required that a CAN FD implementation be compatible with this CAN FD specification as well as with the BOSCH CAN Specification 2.0. In order t