Construct UART Data Frame with Parity Bit

Code

#include <stdio.h>
#include <stdint.h>


typedef struct {
    uint8_t parity_enable : 1;   // 0 = Disabled, 1 = Enabled
    uint8_t parity_type   : 1;   // 0 = Even parity, 1 = Odd parity
    uint8_t reserved      : 6;   // Reserved bits
} UART_Control;

uint8_t create_data_frame(uint8_t data, UART_Control *ctrl){
    if(ctrl->parity_enable == 0){
        return data & 0x7F; // 0b01111111  the MSB (bit 7) is 0, and the remaining 7 bits are data.
    }
    else{
        int count = 0;
        uint8_t parity_bit = 0;
        for(int i = 0; i < 7; i++){
            if (data & (1 << i)) count++;
        }
        if(ctrl->parity_type == 0){ // Even parity
            parity_bit = (count % 2 == 0) ? 0 : 1;
        }
        else{// Odd parity
            parity_bit = (count % 2 == 0) ? 1 : 0;        
        }

        return (parity_bit << 7) | (data & 0x7F);
    }
}

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_data_frame(data, &ctrl);
    printf("frame = 0x%02X", frame);

    return 0;
}

Solving Approach