STM32 printf redirection virtual oscilloscope

KEIL MDK　 Use in DEBUG_VIEWER

#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) 
{
#ifdef DEBUGVIEWER    // Use DEBUG_VIEWER
    if (DEMCR & TRCENA) 
    {
        while (ITM_Port32(0) == 0);
        ITM_Port8(0) = ch;
    }
    return(ch);
#else                // Use Usart  Output Printf
		HAL_UART_Transmit(&huart2,(uint8_t*)&ch,1,0xFFFF);
    return (ch);
#endif
}

Virtual oscilloscope using Shanwai multifunctional debugging assistant

The data transmission format is 0x03 0xFC .....0x03 0xFC

#define CMD_WARE 0x03

void Putbuff(UART_HandleTypeDef *huart,uint8_t *buff,uint32_t len)
{
  while(len--)
  {
    HAL_UART_Transmit(huart,(uint8_t*)buff,1,0xFF);
    buff++;
  }
}

void SendData(void* dat,uint16_t size)
{
	uint8_t  cmdf[2] = {CMD_WARE, ~CMD_WARE};    
	uint8_t  cmdr[2] = {~CMD_WARE, CMD_WARE};   
	Putbuff(&huart2, cmdf, sizeof(cmdf));    
	Putbuff(&huart2, (uint8_t *)dat, size);  
	Putbuff(&huart2, cmdr, sizeof(cmdr));   
}