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 count_ones(uint8_t data)
{
    uint8_t count = 0;

    while(data > 0)
    {
        count++;
        data &= (data-1);
    }

    return count;

}

uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl) {
    // Your logic here
    uint8_t uart_frame = data;
    if(ctrl->parity_enable)
    {
        int ones = count_ones(data);

        if(ctrl->parity_type == 0)
        {
            if(ones % 2 != 0)
            {
                uart_frame |= (1U << 7);
            }
        }
        else
        {
            if(ones % 2 == 0)
            {
                uart_frame |= (1U << 7);
            }
        
        }
    }

    return uart_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