把STM324x9I-EVAL的printf轉到debug viewer顯示

STM324x9I-EVAL的LWIP + RTOS預設是輸出到LCD上

我想要把訊息轉成輸出到debug viewer上
這邊用LwIP_UDPTCP_Echo_Server_Netconn_RTOS這個範例和uVision來修改

1. 打開專案後進到Options for Target設定

2. 把main.h裡面的#define USE_LCD這行Comment掉

//#define USE_LCD

3. 把lcd_log.c裡面的LCD_LOG_PUTCHAR整段Comment掉

4. 把lcd_log_conf.h裡面Redirect the printf to the LCD下面那段整段Comment掉

///* Redirect the printf to the LCD */
//#ifdef __GNUC__
///* With GCC, small printf (option LD Linker->Libraries->Small printf
//   set to 'Yes') calls __io_putchar() */
//#define LCD_LOG_PUTCHAR int __io_putchar(int ch)
//#else
//#define LCD_LOG_PUTCHAR int fputc(int ch, FILE *f)
//#endif /* __GNUC__ */

5. 接著一樣在lcd_log_conf.h裡面加入以下程式

#define ITM_Port8(n)    (*((volatile unsigned char *)(0xE0000000+4*n)))
#define ITM_Port16(n)   (*((volatile unsigned short*)(0xE0000000+4*n)))
#define ITM_Port32(n)   (*((volatile unsigned long *)(0xE0000000+4*n)))
#define DEMCR           (*((volatile unsigned long *)(0xE000EDFC)))
#define TRCENA          0x01000000

struct __FILE { int handle;};
FILE __stdout;
FILE __stdin;

int fputc(int ch, FILE *f)
{
    if (DEMCR & TRCENA)
    {
        while (ITM_Port32(0) == 0);
        ITM_Port8(0) = ch;
    }
    return(ch);
}

6. 在main.c的SystemClock_Config後面加入debug訊息

printf("  test\n\r");

7. Rebuild後接著Ctrl + F5進入Debug

8. 進入Debug後打開Debug viewer

    單步執行到加入printf的地方就能看到訊息輸出在右邊的Debug viewer視窗