Modern electronic equipment is becoming more and more complex. In order to ensure the stability and reliability of the system, it is often necessary to introduce some hardware design for monitoring and protection.Among them, Watchdog is a common and important function, which generally refers to the electronic equipment or circuit, commonly seen in Industrial Routers and Industrial Modems of cellular networks, used to monitor the operation of specific systems or applications to ensure their normal operation. This article will briefly discuss the working principle of watchdog and its application in electronic equipment.
In smart home, smart wearable devices, industrial automation, vehicle systems and other applications, these systems have complex hardware structure and software logic, which are vulnerable to the impact of external environment or the interference of unexpected failures. The watchdog can detect the system abnormality in time and take measures to restore the normal operation of the system.
On systems requiring a high degree of stability and reliability. For example, hard drives, routers, and drones. Many electronic equipment systems are composed of multiple hardware and software, and they operate for a long time, consume a lot of energy, and are more likely to fail.At this time, configuring the watchdog circuit for the equipment can ensure that the equipment can be restarted in time when it fails, and ensure that the equipment is always in an effective operation state.
Watchdog technology, also known as "watchdog timer", is proposed by technicians to solve software anomalies in embedded systems. In embedded systems, some key applications often need to run for a long time, and the whole system must be efficient, stable and reliable.Once the system fails, it may cause serious consequences and irreversible, so it is necessary to introduce a hardware protection technology to minimize the impact of these failures on the system. Watchdog technology is a kind of hardware monitoring technology, which scans and checks the system status by setting a timer to avoid software and hardware anomalies.
Watchdog implementations are typically based on a timer that is reset after system startup and starts counting according to a specified timeout.The timeout period refers to a period of time during which the dog must be fed or the system will be deemed to have failed. After the timeout, the watchdog timer will produce a special response, including resetting the system, shutting down the system, or other emergency measures.
In single chip microcomputer, the realization of watchdog technology is realized by internal or external timer. Some of the microcontroller has been integrated inside the watchdog module, we only need to configure the appropriate parameters can be used. And some single-chip need to use external components to expand.Watchdog technology in single chip microcomputer is usually realized by built-in or external timer, which requires the cooperation of many hardware and software. The hardware needs to design the corresponding circuit connection according to the timer module, and initialize and set the parameters of the watchdog. At the same time, the software needs to write the corresponding protection program to feed the dog and perform the necessary protection operations.In the actual design, it is necessary to determine the way of calling various functions and parameter values according to the technical documents provided by various manufacturers.Block Diagram of MCU System with Built-in Watchdog (Part)
Watchdog technology is an important system protection technology, which helps to avoid the embedded system or microcontroller abnormal or failure caused by the crash and other issues, and ensure the normal operation of electronic equipment. In the actual operation, it is necessary to carefully consider the specific hardware architecture and the mutual coordination with the software design to ensure the accurate control of the watchdog.