Macro-Based Register Config Helper

Code

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

// Define macros here
#define SET_ENA(a, b)  ((a) |= (b))
#define SET_MOD(a, b)   ((a) |= ((b) << 1))
#define SET_SPE(a, b)   ((a) |= ((b) << 3))
#define RESERVED(a)    ((a) &= (0x3F))

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    // Use macros to set fields
    uint16_t reg = 0x0;
    SET_ENA(reg, enable);
    SET_MOD(reg, mode);
    SET_SPE(reg, speed);
    RESERVED(reg);
    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