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;



int count_ones(uint8_t data){
    int count =0;
    for(int i =0; i<7; i++){

        if(data & (1<<i)){
            count++;
        }

    }
    return count;
}



uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl){
    
    //data = data & 0x7f;

    if(ctrl->parity_enable ==0){
        return data;
    }
    int ones = count_ones(data);
    int parity_bit;

    if(ctrl->parity_type == 0){
        parity_bit=(ones % 2 == 0)? 0:1;
    }
    else
        parity_bit =(ones % 2 == 0)? 1:0;

 return( parity_bit<<7) | 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;
}




// --------------------------

// uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl) {
//     uint8_t ans=0;
//     uint8_t dummy = data;
//     int count=0;


//     if(ctrl->parity_enable == 1){
//         while(dummy!=0){
//             if(dummy & 1 == 1 )
//                 count++;
//             dummy>>=1;  
//         }

//         if(ctrl->parity_type == 1 ){
//             if(count%2!=0)
//                 ans = (1<<7) | data;//odd
//             else
//                 ans = (0<<7) | data;//even
//         }
//         else
//             if(count%2!=0)
//                 ans = (0<<7) | data;//odd
//             else
//                 ans = (1<<7) | data;//even

//     }


//     else{
//         ans = (0<<7) | data;
//     }


//     return ans;
// }

Solving Approach