Macro-Based Register Config Helper

Code

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

#define SET_ENABLE(reg, enable) reg &= ~0x01; reg |= enable;
#define SET_MODE(reg, mode) reg &= ~0x06; reg |= mode << 1;
#define SET_SPEED(reg, speed) reg &= ~0x38; reg |= speed << 3;
#define CLEAR_RESERVED(reg) reg &= ~0xc0;

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    uint16_t out = 0;

    SET_ENABLE(out, enable)
    SET_MODE(out, mode)
    SET_SPEED(out, speed)
    CLEAR_RESERVED(out)

    return out;
}

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