Macro-Based Register Config Helper

Code

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

//(x & 0x07)        // 101, fits in 3 bits
//((x & 0x07) << 3) // 101000, now in bits 3–5

// Define macros here
#define SET_ENABLE(x) ((x & 0x01) << 0)
#define SET_MODE(x) ((x & 0x03) << 1)
#define SET_SPEED(x) ((x & 0x07) << 3)


uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    // Use macros to set fields
    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);

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

Solving Approach