Construct UART Data Frame with Parity Bit

Code

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

typedef struct {
    uint8_t parity_enable : 1;
    uint8_t parity_type   : 1;
    uint8_t reserved      : 6;
} UART_Control;

int count_1s(uint8_t data) {
    int count = 0;
    for (int i = 0; i < 8; i++) {
        if (data & (1U << i))
            count++;
    }
    return count;
}

uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl) {
    // Your logic here
    data = data & 0x7F;
    if (ctrl->parity_enable == 0) return data;
    int count = count_1s(data);
    int parity_bit;
    if (ctrl->parity_type == 0) {
        parity_bit = (count % 2 != 0) ? 1 : 0;
    }
    else {
        parity_bit = (count % 2 == 0) ? 1 : 0;
    }

    return data | (parity_bit << 7);
}

int main() {
    uint8_t data;
    scanf("%hhu", &data);  // 7-bit input

    uint8_t parity_enable, parity_type;
    scanf("%hhu %hhu", &parity_enable, &parity_type);

    UART_Control ctrl;
    ctrl.parity_enable = parity_enable;
    ctrl.parity_type = parity_type;

    uint8_t frame = create_uart_frame(data, &ctrl);
    printf("frame = 0x%02X", frame);

    return 0;
}

Solving Approach