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 create_uart_frame(uint8_t data, UART_Control *ctrl) {
    // Your logic here
    {
    uint8_t temp = data & 0x7F;   // ensure 7-bit
    uint8_t count = 0;
    uint8_t parity_bit = 0;

    // If parity disabled → MSB = 0
    if (ctrl->parity_enable == 0)
    {
        return temp;
    }

    // Count number of 1s
    uint8_t t = temp;
    while (t)
    {
        count += (t & 1);
        t >>= 1;
    }

    // Decide parity bit
    if (ctrl->parity_type == 0)   // EVEN
    {
        parity_bit = (count % 2 == 0) ? 0 : 1;
    }
    else                          // ODD
    {
        parity_bit = (count % 2 == 0) ? 1 : 0;
    }

    // Place parity bit at MSB
    return (parity_bit << 7) | temp;
}
}

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;
}