Watchdog reset recovery in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to clear the watchdog reset flag.

Embedded C

if (WDTIFG & [1]) {
    // Clear watchdog reset flag
    WDTIFG &= ~[1];
}

Drag options to blanks, or click blank then click option'

AWDTRST

BWDT_RESET

CWDTIFG

DWDT_FLAG

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong flag name that does not indicate watchdog reset.

Trying to clear the flag incorrectly.

The watchdog reset flag is typically named WDTRST in embedded C for MSP430. Checking this flag helps detect if a watchdog reset occurred.

2fill in blank

medium

Complete the code to reset the watchdog timer counter.

Embedded C

void reset_watchdog() {
    [1] = 0x5A;
    WDTCTL = WDTPW | WDTCNTCL;
}

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AWDTCTL_RESET

BWDT_RESET

CWDT_COUNTER

DWDTCTL

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to reset the watchdog by writing to the wrong register.

Not including the password when writing to the watchdog control register.

Writing the password and the clear bit to WDTCTL resets the watchdog timer counter.

3fill in blank

hard

Fix the error in the watchdog reset detection code.

Embedded C

if ([1] & WDTRST) {
    // Handle watchdog reset
}

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AWDTIFG

BWDTCTL

CWDT_FLAG

DWDT_RESET

Attempts:

3 left

💡 Hint

Common Mistakes

Checking the flag in the wrong register.

Using an undefined flag name.

The watchdog reset flag WDTRST is a bit in the WDTCTL register, so you must check WDTCTL & WDTRST.

4fill in blank

hard

Fill both blanks to create a dictionary that maps reset causes to messages.

Embedded C

const char* reset_messages[] = {
    [[1]] = "Power On Reset",
    [[2]] = "Watchdog Reset"
};

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APORRST

BWDTIFG

CWDTRST

DPWRONRST

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the constants for reset causes.

Using flags instead of reset cause constants.

PWRONRST is the power-on reset cause, and WDTRST is the watchdog reset cause.

5fill in blank

hard

Fill all three blanks to implement watchdog reset recovery logic.

Embedded C

void check_reset_cause() {
    if (WDTCTL & [1]) {
        clear_reset_flag([2]);
        log_event([3]);
    }
}

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AWDTRST

C"Watchdog reset detected"

DWDTIFG

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the reset flag bit and the flag to clear.

Forgetting to log the reset event.

Check the WDTRST bit in WDTCTL, clear the watchdog reset flag, and log a message.