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
    uint8_t result = data ; 
    int count = 0;
    if (ctrl->parity_enable == 0 )
    {
        result &= ~(1 << 7); 
        
    }
    else 
    {
    for (int i = 0 ; i < 7 ; i ++)
    {
        if (data & (1 << i))
            {
                count ++ ; 
            }
    }

    if (ctrl->parity_type == 0)
    {

        if (count % 2 ==0)
        {
            
            result &= ~(1 << 7); 
        }
        else 
        {
            result |= (1 << 7); 
            
        }
    }
        
    else 
    {
        if (count % 2 ==0)
        {
            
            result |= (1 << 7); 
        }
        else 
        {
            result &= ~(1 << 7); 
            
        }
            
    }
    

    }
    return result;
    // else 
    // {
    //     for (int i = 0 ; i < 7 ; i ++)
    //     {
    //         if (data & (1 << i))
    //         {
    //             count ++ ; 
    //         }
    //     }
    //     if (ctrl->parity_type == 0)
    //     {

    //     if (count % 2 ==0)
    //     {
            
    //         result &= ~(1 << 7); 
    //     }
    //     else 
    //     {
    //         result |= (1 << 7); 
            
    //     }
    //     }
        
    //     else 
    //     {
    //         if (count % 2 ==0)
    //     {
            
    //         result |= (1 << 7); 
    //     }
    //     else 
    //     {
    //         result &= ~(1 << 7); 
            
    //     }
            
    //     }
        
        
    // return result;
    // }
    
}

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

 

 

 

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Input

85 1 0

Expected Output

frame = 0x55