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) {
    // Clear the parity bit
    uint8_t frame = data & ~(1U << 7);

    if(ctrl->parity_enable) {
        // Count 1s in data
        int count = 0;
        for(int i = 0; i < 7; i++) {
            count += (data >> i) & 1U;
        }
        // Set parity bit according to type
        if (ctrl->parity_type) {
            if(!(count % 2)) {
                frame |= (1U << 7);
            }
        } else {
            if((count % 2)) {
                frame |= (1U << 7);
            }
        }
        
    }
    return 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