Macro-Based Register Config Helper

Code

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

#define ENABLE_POS   0
#define MODE_POS     1
#define SPEED_POS    3

#define ENABLE_MASK  0x01
#define MODE_MASK    0x03
#define SPEED_MASK   0x07

#define SET_ENABLE(x)  (((uint16_t)((x) & ENABLE_MASK)) << ENABLE_POS)
#define SET_MODE(x)    (((uint16_t)((x) & MODE_MASK))   << MODE_POS)
#define SET_SPEED(x)   (((uint16_t)((x) & SPEED_MASK))  << SPEED_POS)

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

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