Keil stm32 printf到Debug窗口

使用JlinkV8+Keil4
1、在main.c输入以下代码

#include <stdio.h>  

#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  

//半主机模式必须定义这个
struct __FILE
{
    int handle;
};
FILE __stdout;
FILE __stdin;  

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

        ITM_Port8() = ch;
    }
    return(ch);
}  

2、必须使用SW模式

3、打开Trace

4、运行效果