C언어 코딩 질문

There are several issues in your code:

​

1. **Redefining `main` function**: You have multiple `main` functions defined in your code. Only one `main` function is allowed in a C program.

​

2. **Multiple declarations of variables**: You have declared multiple variables with the same name, such as `led`. Declare each variable only once.

​

3. **Undefined function `shift_r`**: In the first code

snippet, you call the `shift_r` function, but it is not defined anywhere in your code.

​

4. **Undefined function `shift_rl`**: Similarly, in the fifth code snippet, you call the `shift_rl` function,

but it is not defined.

​

5. **Incorrect bitwise operations**: In the fourth code snippet, the bitwise left shift (<<) is used incorrectly in the line `led=(led<<1) l led`. It should be `led=(led<<1) | led` to perform a logical OR operation.

​

6. **Incorrect constant initialization**: In the sixth

code snippet, the array `FND` is initialized with values that are not enclosed in braces. The correct syntax is `unsigned char FND[4]={0x92, 0x89, 0xc0, 0xc4};`.

​

Here's a modified version of your code addressing these issues:

​

```c

#include <mega128.h>

#include <delay.h>

​

unsigned char led;

​

void main() {

DDRA = 0xff;

led = 0x01;

​

do {

PORTA = led;

delay_ms(500);

led = (led << 1);

if (led == 0x80) {

PORTA = led;

delay_ms(500);

led = 0x01;

}

} while (1);

}

```