Macro-Based Register Config Helper

Code

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

// Define macros here
#define SET_BITS(start_bit, end_bit) ((1U << (end_bit - start_bit + 1)) - 1U)

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    // Use macros to set fields
    uint16_t reg = 0;
    uint16_t mask = enable & SET_BITS(0, 0);
    reg |= mask;
    mask = (mode & SET_BITS(1, 2)) << 1;
    reg |= mask;
    mask = (speed & SET_BITS(3, 5)) << 3;
    reg |= mask;

    return reg;
}

int main() {
    uint8_t enable, mode, speed;
    scanf("%hhu %hhu %hhu", &enable, &mode, &speed);

    uint16_t reg = build_register(enable, mode, speed);
    printf("%u", reg);
    return 0;
}

Solving Approach