Macro-Based Register Config Helper

Code

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

// Define macros here
#define SET_ENABLE(reg, val)  ((reg) | ((val & 1) << 0))
#define SET_MODE(reg, val)    ((reg) | ((val & 0x3) << 1))
#define SET_SPEED(reg, val)   ((reg) | ((val & 0x7) << 3))

uint16_t build_register(uint8_t enable, uint8_t mode, uint8_t speed) {
    uint16_t reg = 0;            // Initialize register
    reg = SET_ENABLE(reg, enable);
    reg = SET_MODE(reg, mode);
    reg = 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

• Initialize reg = 0 → RESERVED bits 0.
• Set fields using macros:
  • ENABLE → bit 0
  • MODE → bits 1–2
  • SPEED → bits 3–5
• Combine with OR (|).
• Return reg.