AND for masking bits in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to mask the lower 4 bits of the variable value.

Embedded C

unsigned char masked = value [1] 0x0F;

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

A|

B^

C~

D&

Attempts:

3 left

💡 Hint

Common Mistakes

Using OR (|) instead of AND (&) will not mask bits correctly.

Using XOR (^) changes bits instead of masking.

Using NOT (~) inverts bits, not mask.

The AND operator (&) is used to mask bits. Using & 0x0F keeps only the lower 4 bits of value.

2fill in blank

medium

Complete the code to mask bits 4 to 7 (upper nibble) of value.

Embedded C

unsigned char masked = value [1] 0xF0;

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

A&

B<<

C^

D|

Attempts:

3 left

💡 Hint

Common Mistakes

Using OR (|) will set bits instead of masking.

Using shift operators (<<) alone does not mask bits.

Using XOR (^) flips bits, not mask.

Using AND (&) with 0xF0 keeps bits 4 to 7 and clears bits 0 to 3.

3fill in blank

hard

Fix the error in the code to mask bits 2 and 3 of value.

Embedded C

unsigned char masked = value [1] 0x0C;

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

A|

B&

C<<

D>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using OR (|) sets bits instead of masking.

Using shift operators (<<, >>) do not mask bits directly.

AND (&) with 0x0C (binary 00001100) keeps bits 2 and 3 only.

4fill in blank

hard

Fill both blanks to create a mask that keeps bits 1, 3, and 5 of value.

Embedded C

unsigned char mask = [1];
unsigned char masked = value [2] mask;

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

A0x2A

B&

C|

D0x15

Attempts:

3 left

💡 Hint

Common Mistakes

Using OR (|) instead of AND (&) to apply the mask.

Using wrong mask value that does not match bits 1, 3, and 5.

0x2A in hex is binary 00101010, which has bits 1, 3, and 5 set. AND (&) with this mask keeps those bits.

5fill in blank

hard

Fill all three blanks to mask bits 0, 2, and 4 of value and store the result in masked.

Embedded C

unsigned char mask = [1];
unsigned char masked = value [2] mask [3] 0;

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

A0x15

B&

C+

D|

Attempts:

3 left

💡 Hint

Common Mistakes

Using OR (|) instead of AND (&) to mask bits.

Using wrong mask value.

Adding a non-zero value changes the result.

0x15 (binary 00010101) masks bits 0, 2, and 4. AND (&) applies the mask. Adding 0 does not change the result.