Register bit manipulation patterns in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set bit 3 of the register.

Embedded C

REG |= (1 << [1]);

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

A3

B2

C4

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong bit number.

Forgetting to use parentheses around (1 << bit).

Bit 3 is set by shifting 1 left by 3 positions.

2fill in blank

medium

Complete the code to clear bit 5 of the register.

Embedded C

REG &= ~(1 << [1]);

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

A2

B3

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 instead of 1 for the mask.

Not negating the mask before AND operation.

To clear bit 5, shift 1 left by 5 and invert it with ~.

3fill in blank

hard

Fix the error in the code to toggle bit 2 of the register.

Embedded C

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

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

A|

B^

C&

D~

Attempts:

3 left

💡 Hint

Common Mistakes

Using |= which sets the bit instead of toggling.

Using &= which clears bits.

Toggle a bit using XOR (^=) with the bit mask.

4fill in blank

hard

Fill both blanks to check if bit 4 is set in the register.

Embedded C

if ((REG [1] (1 [2] 4)) != 0) {
    // bit 4 is set
}

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

A&

B|

C<<

D>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using | instead of & which always returns non-zero.

Using right shift >> instead of left shift <<.

Use bitwise AND (&) with 1 shifted left (<<) by 4 to check bit 4.

5fill in blank

hard

Fill all three blanks to set bits 0, 2, and 7 in the register.

Embedded C

REG |= ([1] << 0) | ([2] << 2) | ([3] << 7);

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

A1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 instead of 1 for the bit mask.

Not combining masks with OR operator.

Set bits by shifting 1 to each bit position and OR-ing them together.