Keil Print输出

• 在keil中使能print输出

• C++、ASM标签添加DEBUG_ENABLE_SEMIHOST选项

• 选中use microLib

  #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
  
  struct __FILE { int handle; /* Add whatever you need here */ };
  FILE __stdout;
  FILE __stdin;
  
  int fputc(int ch, FILE *f) {
    if (DEMCR & TRCENA) {
      while (ITM_Port32(0) == 0);
      ITM_Port8(0) = ch;
    }
    return(ch);
  }