Macro-Based Register Config Helper

Code

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

// --- Bit Positions ---
#define ENABLE_POS   0
#define MODE_POS     1
#define SPEED_POS    3

// --- Bit Masks ---
#define ENABLE_MASK  (0x01 << ENABLE_POS)   // 1 bit
#define MODE_MASK    (0x03 << MODE_POS)     // 2 bits
#define SPEED_MASK   (0x07 << SPEED_POS)    // 3 bits

// --- Macros to Set Fields ---
#define SET_ENABLE(val)   ((uint16_t)((val & 0x01) << ENABLE_POS))
#define SET_MODE(val)     ((uint16_t)((val & 0x03) << MODE_POS))
#define SET_SPEED(val)    ((uint16_t)((val & 0x07) << SPEED_POS))

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);

    // RESERVED bits (6–7) left as 0
    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