20. Clear Specific Bits in a 32-bit Register

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

uint32_t clear_bits(uint32_t reg, uint8_t pos, uint8_t len) {
    // Step 1: Create a mask with 'len' number of 1s
    uint32_t mask = (1U << len) - 1;

    // Step 2: Shift the mask to the required position
    mask = mask << pos;

    // Step 3: Invert the mask so target bits become 0
    mask = ~mask;

    // Step 4: AND with register to clear the bits
    return reg & mask;
}

int main() {
    uint32_t reg;
    uint8_t pos, len;

    scanf("%u %hhu %hhu", &reg, &pos, &len);
    printf("%u", clear_bits(reg, pos, len));

    return 0;
}