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;

uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl) {
    uint8_t frame = 0;
    data &= 0x7F;
    if(ctrl->parity_enable == 0){
        frame = data;
    }
    else if(ctrl->parity_enable == 1){
        int cnt = 0;
        uint8_t tmp = data;
        for(int i = 0; i < 7; i++){
            if(tmp & 1){
                cnt++;
            }
            tmp >>= 1;
        }

        uint8_t parity_bit;

        if(ctrl->parity_type == 0){
            parity_bit = cnt % 2;
        }
        else if(ctrl->parity_type == 1){
            parity_bit = !(cnt % 2);
        }
        frame = (parity_bit << 7) | data;
    }
    return frame;
}

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