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
    uint8_t parity = 0;
    uint8_t ones_count = 0;

    /* Use only 7-bit data */
    data &= 0x7F;

    /* Count number of 1s */
    for (int i = 0; i < 7; i++)
    {
        if (data & (1 << i))
            ones_count++;
    }

    if (ctrl->parity_enable)
    {
        if (ctrl->parity_type == 0)
        {
            /* Even parity */
            parity = (ones_count % 2);
        }
        else
        {
            /* Odd parity */
            parity = !(ones_count % 2);
        }

        /* Place parity at MSB (bit 7) */
        return (parity << 7) | data;
    }
    else
    {
        /* No parity */
        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