62. Decode Status Register into Human-Readable Flags

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

const char *flag_names[8] = {
    "Power On",
    "Error",
    "Tx Ready",
    "Rx Ready",
    "Overheat",
    "Undervoltage",
    "Timeout",
    "Reserved"
};

void decode_status(uint8_t status_reg) {
    for (int i = 0; i < 8; i++) {
        if ((status_reg >> i) & 1) {
            printf("%s\n", flag_names[i]);
        }
    }
}

int main() {
    uint8_t reg;
    scanf("%hhu", &reg);
    decode_status(reg);
    return 0;
}

What is this about?

You’re decoding an 8-bit status register, where each bit tells you whether a system condition is active — like flags from a sensor or peripheral.

Why it’s important in firmware?

• Many peripherals return status in register bits
• Developers need to interpret bit-level feedback quickly
• This maps low-level binary data to user-meaningful outputs

Solution Logic

• Use a lookup table (flag_names[])
• Shift each bit to LSB, check if set
• Print the corresponding name only if bit = 1