Validate Configuration Register Layout

Code

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    unsigned short reg = cfg->reg;

    if((reg & 0x0001) == 0)
      return 0;

    unsigned short priority = (reg >> 2) & 0x03;
    if(priority == 3)
      return 0;

    if(reg & 0xFFF0)
      return 0;

    return 1;
}

int main() {
    ConfigRegister cfg;
    scanf("%hx", &cfg.reg);

    int result = validate_config(&cfg);
    printf("%d", result);

    return 0;
}

Solving Approach

• cfg->reg accesses the register using pointer.
• (reg & 0x0001) checks Enable bit.
• ((reg >> 2) & 0x3) extracts Priority bits.
• (reg & 0xFFF0) ensures bits 4–15 are zero.