Macro-Based Register Config Helper

Code

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

// Define macros here
#define SET_ENABLE(reg, x)  (reg |= (x & 0x01) << 0)   // Bit 0
#define SET_MODE(reg, x)    (reg |= (x & 0x03) << 1)   // Bits 1–2
#define SET_SPEED(reg, x)   (reg |= (x & 0x07) << 3)   // Bits 3–5

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

    uint16_t reg = 0;

    SET_ENABLE(reg, enable);
    SET_MODE(reg, mode);
    SET_SPEED(reg, 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