XOR for toggling bits in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to toggle the 3rd bit of the variable flags.

Embedded C

flags = flags [1] (1 << 2);

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

A&

B|

C^

D<<

Attempts:

3 left

💡 Hint

Common Mistakes

Using & or | instead of ^ will not toggle bits correctly.

Using XOR (^) with a bit mask toggles the targeted bit.

2fill in blank

medium

Complete the code to toggle the least significant bit of status.

Embedded C

status [1]= 1;

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

A^

B&

C|

D<<

Attempts:

3 left

💡 Hint

Common Mistakes

Using &= or |= will not toggle the bit.

The ^= operator toggles the bit specified by the mask.

3fill in blank

hard

Fix the error in toggling the 5th bit of control.

Embedded C

control = control [1] (1 << 4);

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

A^

B<<

C|

D&

Attempts:

3 left

💡 Hint

Common Mistakes

Using | sets the bit instead of toggling it.

XOR (^) toggles the bit; using | sets it instead.

4fill in blank

hard

Fill both blanks to toggle the 2nd bit and check if it was set before toggling.

Embedded C

if ((flags [1] (1 << 1)) != 0) {
    flags [2]= (1 << 1);
}

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

A&

B^

C|

D<<

Attempts:

3 left

💡 Hint

Common Mistakes

Using | to check bits is incorrect.

Using |= toggles incorrectly.

Use & to check if the bit is set, then ^= to toggle it.

5fill in blank

hard

Fill all three blanks to toggle the 4th bit of reg only if it is currently set.

Embedded C

if (reg [1] (1 << 3)) {
    reg [2]= (1 << 3);
    result = reg [3] (1 << 3);
}

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

A&

B^

C|

D<<

Attempts:

3 left

💡 Hint

Common Mistakes

Using | instead of & to check or read bits.

Using |= instead of ^= to toggle bits.

Use & to check the bit, ^= to toggle it, and & to read the bit value.