Practical 16-Bit External Bus Expansion for 8-Bit Microcontrollers

Practical 16-Bit External Bus Expansion for 8-Bit Microcontrollers

1 8-Bit/16-Bit Bus Timing Analysis 1.1 8-Bit Microcontroller Bus Timing There are many 8-bit microcontrollers with external buses, such as the 51 series and AVR series. This article takes the W77E58 as an example. The W77E58 is an enhanced 51 microcontroller introduced by Winbond, with a maximum operating clock of 40 MHz. At the same … Read more

Selected System Design: FPGA-Based CAN Bus Controller Design

Today, I bring you the design of a CAN bus controller based on FPGA. Due to the lengthy content, it is divided into three parts. Today, I present the third part, followed by the next one, which covers the program simulation and testing, as well as a summary. Without further ado, let’s get started. I … Read more

Why Is the CAN Bus Termination Resistor 120Ω?

Why Is the CAN Bus Termination Resistor 120Ω?

Source | Vehicle Terminal Function of the Termination Resistor The CAN bus termination resistor serves three purposes: 1. Enhance anti-interference capability, allowing high-frequency low-energy signals to dissipate quickly. 2. Ensure the bus quickly enters a dormant state, allowing the energy of parasitic capacitance to dissipate faster; 3. Improve signal quality, placed at both ends of … Read more

Detailed Explanation of Automotive CAN Bus Technology

Detailed Explanation of Automotive CAN Bus Technology

Editor ▎ Wang Yan Review ▎Yu Yongchu Jinfen Mall Popular Book Rankings ☞ Jinfen’s Favorite Book Rankings ☞ Mechanical Book Rankings ☞ Production Management Rankings ☞ Design Software Rankings How to Quickly Publish Articles in the ‘Automotive Engineer’ Magazine October 2022 Automotive Production and Sales: Continued Year-on-Year Growth, New Energy Vehicles Set New Historical Highs … Read more

Differences Between RS-485 and CAN-bus

Differences Between RS-485 and CAN-bus

In bus systems, both RS-485 and CAN-bus are commonly used buses, each with unique characteristics and application scenarios, widely applied. Today, let’s discuss their differences. 1. What is RS-485? RS-485 is a serial communication protocol that has been around since the mid-1980s, originally defined for industrial market applications. It uses differential signaling with negative logic, … Read more

Regular Maintenance Methods for CAN Bus Faults – Part 1

Regular Maintenance Methods for CAN Bus Faults - Part 1

When the CAN bus malfunctions or data transmission is abnormal, various strange fault phenomena often occur, such as abnormal dashboard displays, inability to start the vehicle, failure to turn off after starting, decreased vehicle performance, and loss of certain electronic control system functions. This is because relevant data or information is transmitted through the CAN … Read more

Common Maintenance Methods for Automotive CAN Bus Failures – Part 2

Common Maintenance Methods for Automotive CAN Bus Failures - Part 2

4. Short Circuit of CAN L to Ground When a short circuit occurs between CAN L and ground, due to the fault tolerance characteristics of the CAN bus, the entire CAN network may be unable to communicate or generate related fault codes. However, for certain vehicle models, such as Haima, the fault tolerance characteristics of … Read more

Impact of Not Using Termination Resistors in CAN Bus

Impact of Not Using Termination Resistors in CAN Bus

Before performing CAN bus communication, it is important to ensure proper bus configuration, such as termination resistors. They are crucial components that affect bus communication. Below, we will analyze the effects of not using termination resistors solely from the perspective of signal amplitude and time constant, without considering signal integrity. Termination Resistor Requirements According to … Read more

Common CAN Bus Faults and Troubleshooting Methods

Common CAN Bus Faults and Troubleshooting Methods

To begin with, let’s recall what the normal operating voltages of CAN_H and CAN_L are. When there are issues with the CAN bus, it is often accompanied by various faults, such as abnormal dashboard displays, the vehicle failing to start, or failing to turn off after starting, etc. We will mainly introduce the 8 common … Read more

Common Faults of CAN Bus and Multimeter Inspection Methods

Common Faults of CAN Bus and Multimeter Inspection Methods

Detection Methods for CAN Bus ① Before checking the data bus system, ensure that all electronic control units (ECUs) connected to the data bus have no functional faults. Functional faults refer to those that do not directly affect the data bus system but will impact the functional process of a certain system. For example, if … Read more