From CAN to CAN FD: Application of ADTF in Automotive Networks

With the development of automotive electronics technology, more and more electronic devices are installed on vehicles. Most of these devices use point-to-point communication , which also leads to the existence of huge wiring harnesses in the car. This makes it difficult to manufacture and install cars and further reduces the configuration space of cars. The car bus gradually begins to develop in the direction of networking .

In this context, CAN (Controller Area Network ) bus came into being. With its high reliability and flexibility, it has become an indispensable part of the automotive communication system, carrying key tasks such as vehicle control, monitoring and diagnosis.

Technology evolution: from CAN to CAN FD

With the continuous development of technology, the traditional CAN bus has gradually shown its limitations in data transmission rate and bandwidth. Specifically, the maximum baud rate of the traditional CAN bus is 1Mbit/s, and the maximum valid data field in the data frame is 8 bytes.

This design met the needs of vehicle control and monitoring in the early days, but as the complexity of vehicle systems increased, the demand for higher data transmission rates and larger data capacities became increasingly urgent.

Therefore, CAN FD (CAN with Flexible Data-Ra te ) was introduced. CAN FD has achieved major technological breakthroughs while maintaining the excellent characteristics of CAN:

Variable data bit rate

CAN FD introduces a variable baud rate mechanism for the data segment. Its transmission rate is generally 5-8Mbit/s. The baud rate of this segment is variable, while the rest of the segment still uses the original CAN rate, thereby greatly improving the data transmission rate while maintaining compatibility.

Expanded effective data field

CAN FD expands the effective data field in the data frame to 64 bytes, which significantly increases the transmission volume of single-frame data compared to the 8 bytes of traditional CAN, making communication more flexible, fast and reliable.

New CRC algorithm

In order to accommodate a larger data domain and improve the accuracy of error detection , CAN FD uses a new CRC algorithm and optimizes the fill bit rules to reduce the error frame miss detection rate.

New frame structure

CAN FD adds FDF, BRS and ESI bits in the control field, which are used to distinguish CAN messages from CAN FD messages and determine whether to convert to a variable rate. At the same time, the DLC encoding method is changed from linear to stepped to accommodate a larger data length.

ADTF: supports comprehensive CAN communication protocols

ADTF (AUTOMO TI VE DATA & TIME-TRIGGERED FRAMEWORK) is an automotive data and time-triggered framework that can be used to develop vehicle driver assistance systems. It provides a range of functions and tools to support the development and testing of vehicle automation and driver assistance systems. ADTF can be used for rapid prototyping, simulation , data logging and verification (post-processing).

Figure 1: ADTF framework

In terms of bus, ADTF has multiple toolboxes to support its simulation and testing, such as ADTF Device Toolbox, ADTF Calibration Toolbox, etc.

Provides ARXML database file bus parsing in ADTF Device Toolbox, supports automotive buses (CAN, CANFD, Flexray, Ethernet ), Vector® devices, signal processing and visualization, etc.

XCP communication with ECUs is supported in ADTF Calibration Toolbox through multiple filters for communication via CAN, FlexRay, or Ethernet.

Combined with the above toolboxes, ADTF can be applied in the following areas:

Automotive electronic system development

ADTF is widely used in the development of automotive electronic control units (ECUs), including engine control, chassis control, body electronics, etc.

Simulation and testing

In the simulation and testing of automotive electronic systems, ADTF can simulate bus communications and perform system-level and component-level testing.

Data recording and analysis

ADTF supports data logging function, which can capture and store data on the bus for subsequent analysis and fault diagnosis.

Application practice: technical implementation of ADTF

One of ADTF’s strengths is the analysis of bus data. For example, the data collected by CAN FD can be analyzed and visualized based on the DBC configuration, as shown in Figures 2 and 3.

Figure 2: CAN FD data playback engineering diagram

Figure 3: CAN FD data analysis results

In addition, ADTF supports the parsing of ARXML CANFD data under the AUTOSAR architecture, as shown in Figures 4 and 5.

Figure 4: ARM XL CANFD data playback engineering diagram![image.png]

Figure 5: ARMXL CANFD data analysis effect display

ADTF software has become an important tool in the field of automotive electronics development with its powerful functions, high flexibility and professional technical support. Whether in product development, system integration or test verification, ADTF can provide effective solutions to accelerate the development process of automotive electronic systems.