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) {
    // Your logic here

    // Parity enable is 0, return data 
    if(ctrl->parity_enable == 0){
        return (~(1U << 7)) & data; 
    }

    // Count 1s
    uint8_t copy = data;
    uint8_t count = 0;
    for(int i = 0; i <= 7; i++){
        if(copy & 1U){
            count++;
        }
        copy >>= 1;
    }

    // 1s are even && even parity
    if(((count % 2) == 0) && (ctrl->parity_type == 0)){
        return (~(1U << 7)) & data;
    }

    // 1s are odd && even parity
    if(((count % 2) == 1) && (ctrl->parity_type == 0)){
        return (1U << 7) | data;
    }

    // 1s are even && odd parity
    if(((count % 2) == 0) && (ctrl->parity_type == 1)){
        return ((1U << 7)) | data;
    }

    // 1s are odd && odd parity
    if(((count % 2) == 1) && (ctrl->parity_type == 1)){
        return (~(1U << 7)) & data;
    }

    return 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;
}

Solving Approach