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) {
    // Your logic here
    if(ctrl->parity_enable == 0) return data;
    else{
        uint8_t reg = data;
        int cnt = 0;
        while (reg)
        {   
            if(reg & 0x1) ++cnt;
            reg = reg >> 1;
            // printf("cnt = %d\n", cnt);
            // printf("%u\n", reg);
        }
        data &= ~(1 << 7);
        // printf("%u\n", data);
        if(ctrl->parity_type == 0){
            if(cnt % 2 != 0) data |= (1 << 7);
        }
        else {
            if(cnt % 2 == 0) data |= (1 << 7);
        }
    }
    
    return data;
}

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