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) {
    int count = 0;
    
    if (ctrl->parity_enable == 0) {
        // Parité désactivée → bit 7 = 0
        return data & ~(1 << 7);
    } else {
        // Compter les 1 dans les 7 bits de données
        for (int i = 0; i < 7; i++) {
            if (data & (1 << i)) count++;
        }

        if (ctrl->parity_type == 0) { // Parité paire
            if (count % 2 == 0) {
                return data & ~(1 << 7); // MSB = 0
            } else {
                return data | (1 << 7);  // MSB = 1
            }
        } else { // Parité impaire
            if (count % 2 == 0) {
                return data | (1 << 7);  // MSB = 1
            } else {
                return data & ~(1 << 7); // MSB = 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;
}