76. Construct UART Data Frame with Parity Bit

#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 Count(uint8_t data)
{
    int cnt = 0;
    for(int i=0;i<8;i++) cnt += (data >> i) & 1;
    return cnt;
}

uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl) {
    
    data &= 0x7F;

    if(ctrl->parity_enable == 0) return data;
    else
    {
        uint8_t parityBit = 0;
        uint8_t count = Count(data);
        if(ctrl->parity_type)
        {
            if(count%2 == 0) parityBit = 1;
        }
        else if(count%2 != 0) parityBit = 1;
        return (parityBit<<7) | data;
    }

    return 0;
}

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;
}