Macro-Based Register Config Helper

Code

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

#define ENABLE_MASK   (1u << 0)
#define MODE_MASK     (3u << 1)   // 2 bits
#define SPEED_MASK    (7u << 3)   // 3 bits

#define SET_ENABLE(x)   ((x ? ENABLE_MASK : 0))
#define SET_MODE(x)     (((x << 1) & MODE_MASK))
#define SET_SPEED(x)    (((x << 3) & SPEED_MASK))

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    uint16_t reg = 0;
    reg |= SET_ENABLE(enable);
    reg |= SET_MODE(mode);
    reg |= SET_SPEED(speed);
    return reg;
}

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

Solving Approach