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) {
    if (ctrl->parity_enable) {
        // Calculate the XOR sum of the 7 data bits (0 to 6)
        // This bit is 0 if bit_count is even, 1 if bit_count is odd
        uint8_t parity_bit = (data ^ (data >> 1) ^ (data >> 2) ^ (data >> 3) ^ (data >> 4) ^ (data >> 5) ^ (data >> 6)) & 1;

        if (ctrl->parity_type == 1) { // Odd Parity: Invert the calculated parity
            parity_bit = !parity_bit;
        }

        // Clear the MSB (bit 7) of the data, just in case
        data &= 0x7F;

        // Set the calculated parity bit at the MSB (bit 7)
        if (parity_bit) {
            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