Extract a Bit Field from a 32-bit Register

Code

#include <stdio.h>
#include <stdint.h>

uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len) {
    // Your code here
    uint32_t mask = 0;
    uint8_t i;
    for ( i = pos; i < ( pos + len ); i++ )
    {
        mask |= ( 1U << i );
    }
    reg &= mask;
    reg >>= pos;
    return reg;
}
int main() {
    uint32_t reg;
    uint8_t pos, len;
    scanf("%u %hhu %hhu", &reg, &pos, &len);
    printf("%u", extract_field(reg, pos, len));
    return 0;
}

Solving Approach

1. Creating a 32-bit mask

2. Then only the given position and length setting the bits to 1 and rest of the bits 0 using for loop

3. Then anding ("AND") with the generated mask

4. Then shifting by the given position so that preceding bits will be set to 0