INTEL WATCHDOG TIMER DEVICE MANAGER PLUS

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INTEL WATCHDOG TIMER DEVICE MANAGER SOFTWARE

This software architecture is common in many embedded systems with low-end processors and behaviors based on a single operational frequency. Here we have a single infinite loop that controls the entire behavior of the system. Similarly, the software must restart the watchdog timer at a regular rate, or risk being restarted.ДЄ simple example is shown in Listing 1.

But he must keep kicking the dog at regular intervals to avoid a bite. If he keeps kicking the dog, it canвЂ™t ever bite him. The process of restarting the watchdog timerвЂ™s counter is sometimes called вЂњkicking the dog.вЂќ The appropriate visual metaphor is that of a man being attacked by a vicious dog. In either case, the output from the watchdog timer is tied directly to the processorвЂ™s reset signal.

However, it could also be included within the same chip as the CPU. As shown, the watchdog timer is a chip external to the processor. The processor (and the embedded software itвЂ™s running) will be restarted as if a human operator had cycled the power.ДЇigure 1 shows a typical arrangement. If the counter ever reaches zero before the software restarts it, the software is presumed to be malfunctioning and the processorвЂ™s reset signal is asserted. The embedded software selects the counterвЂ™s initial value and periodically restarts it. Generally speaking, a watchdog timer is based on a counter that counts down from some initial value to zero. In other cases, the speed with which a human operator might reset the system would be too slow to meet the uptime requirements of the product.ДЄ watchdog timer is a piece of hardware that can be used to automatically detect software anomalies and reset the processor if any occur. If their software ever hangs, such systems are permanently disabled. Some embedded designs, such as space probes, are simply not accessible to human operators. ItвЂ™s not usually possible to wait for someone to reboot them if the software hangs. Most embedded systems need to be self-reliant. For those embedded systems that canвЂ™t be constantly watched by a human, watchdog timers may be the solution.

Intel watchdog timer device manager