Abstract : The FlexRay bus, with its high speed and high reliability, has received high attention from the automotive industry and will be widely used in the X-by-Wire field. This paper studies a design method for a FlexRay bus node using the Freescale HCS12 series microcontroller MC9S12DG128B as the main controller. The overall system structure block diagram, partial hardware connection diagram, and software design flowchart are presented. The configuration method of the FlexRay bus controller module is also studied. The entire system is based on the MC9S12DG128B, using the MFR4310 as the FlexRay bus controller and the TJA1080 as the FlexRay bus transceiver. This scheme is simple to manufacture and facilitates the realization of in-vehicle drive-by-wire operation (X-by-Wire). Keywords : FlexRay bus; MC9S12DG128B; MFR4310; TJA1080 1. Introduction FlexRay is a registered trademark of DaimlerChrysler AG. In 2000, the FlexRay Consortium was established, with members including DaimlerChrysler, General Motors, BMW, Freescale Semiconductor, NXP Semiconductors, Bosch, and Volkswagen. The maximum performance limit of a CAN network is 1 Mbps. In contrast, FlexRay can achieve a maximum data rate of 10 Mbps on two channels, with a total data rate of 20 Mbit/s. FlexRay supports various topologies, such as bus, star, and hybrid topologies. Furthermore, FlexRay can perform synchronous (real-time) and asynchronous data transmission to meet the needs of various systems in vehicles, such as distributed control systems which typically require real-time data transmission. FlexRay can operate not only as a single-channel system like CAN and LIN networks, but also as a dual-channel system. Dual-channel systems can transmit data through redundant networks—ensuring high system reliability. Therefore, FlexRay can provide the required speed and reliability for next-generation in-vehicle control systems, hence it is considered the "rising star" of in-vehicle buses among many. [Full text download of FlexRay bus node design based on MC9S12DG128B]