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) {
int count=0;
int dc = data;
int p_e = ctrl->parity_enable;
int p_t = ctrl->parity_type;
while(dc>0){
    dc &= (dc-1);
    count++;
}
if (!p_e) {return data;}
if (p_e && p_t && count%2==0) {return data|=0x80; }
if (p_e && !p_t && count%2) {return data|=0x80; }
return 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;
}

Solving Approach

 

 

 

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Input

85 1 0

Expected Output

frame = 0x55