Macro-Based Register Config Helper

Code

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

// Field positions and masks
#define ENABLE_POS   0
#define ENABLE_MASK  (1U << ENABLE_POS)

#define MODE_POS     1
#define MODE_MASK    (0x3U << MODE_POS)   // 2 bits (bits 1–2)

#define SPEED_POS    3
#define SPEED_MASK   (0x7U << SPEED_POS)  // 3 bits (bits 3–5)

// Macros to set fields
#define SET_ENABLE(x)   ((x & 0x1U) << ENABLE_POS)
#define SET_MODE(x)     ((x & 0x3U) << MODE_POS)
#define SET_SPEED(x)    ((x & 0x7U) << SPEED_POS)

// Combine all fields into a 16-bit register
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