Feeding (kicking) the watchdog in Embedded C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of feeding (kicking) the watchdog in embedded systems?

Feeding the watchdog prevents the system from resetting by signaling that the program is running correctly and not stuck.

beginner

How often should the watchdog be fed?

The watchdog should be fed regularly within its timeout period to avoid system reset.

beginner

What happens if the watchdog is not fed in time?

If the watchdog is not fed before the timeout, it triggers a system reset to recover from potential software faults.

intermediate

Show a simple C code snippet to feed the watchdog.

Example:

void feed_watchdog() {
    WDT->CLEAR = 0xA5; // Write specific value to clear watchdog timer
}

beginner

Why is feeding the watchdog compared to 'kicking' it?

Because feeding the watchdog resets its timer, similar to kicking a dog to keep it active and prevent it from barking (resetting).

What is the main role of a watchdog timer in embedded systems?

A Manage power consumption

B Increase system speed

C Store user data

D Reset the system if software hangs

The watchdog timer resets the system if the software stops responding.

What must a program do to prevent the watchdog from resetting the system?

A Feed (kick) the watchdog regularly

B Disable the watchdog permanently

C Increase the watchdog timeout to maximum

D Ignore the watchdog

Regular feeding tells the watchdog the system is running fine.

What happens if the watchdog is not fed in time?

A Watchdog disables itself

B System reset occurs

C System speed doubles

D Nothing happens

Failing to feed the watchdog causes a system reset to recover from faults.

Which of these is a common method to feed the watchdog in C code?

A Writing a specific value to a watchdog register

B Calling printf()

C Turning off interrupts

D Resetting the CPU manually

Feeding the watchdog usually involves writing a special value to its control register.

Why is the watchdog called a 'watchdog'?

A Because it stores data securely

B Because it barks when the system is slow

C Because it watches the system and resets it if it misbehaves

D Because it controls the clock speed

It monitors the system and resets it if the software stops responding.

Explain in your own words what feeding (kicking) the watchdog means and why it is important.

Think about how the watchdog timer works to keep the system safe.

Describe what could happen if an embedded program forgets to feed the watchdog on time.

Consider the watchdog as a safety guard for the system.