Description: A watchdog timer is a critical component in embedded systems used to monitor the operation of running software. Its primary function is to trigger a system reset if the software fails to respond within a specified time, helping to prevent system hangs or failures. This timer operates independently of the software being monitored, allowing it to detect issues even if the software is in a non-operational state. It is commonly implemented in various architectures, where the timer can be configured to initiate a system reset or execute a recovery procedure if the software does not complete its task within the stipulated time. The implementation of a watchdog timer is essential for ensuring the stability and reliability of critical systems, such as those used in automotive, medical, and aerospace applications. Additionally, its design can vary between kernel mode and user mode, where in kernel mode it has full access to system resources, while in user mode it operates under restrictions to protect the integrity of the operating system. This duality allows the watchdog timer to be a versatile and robust tool in error management and recovery for embedded systems.
