printf will miss some data during large amount of print

Forum|Forum|5 years ago
September 22, 2020
5 replies
1337 views

I am using nucleo-H473ZI2 with CubeIDE. When I was trying to print a 1024-long int array, the SWV ITM Data Console will not be giving me all 1024 values.

I implement printf to ITM Stimulus port by writing this function in main.c:

int _write(int file, char *ptr, int len)
{
 /* Implement your write code here, this is used by puts and printf for example */
 int i=0;
 for(i=0 ; i<len ; i++)
 ITM_SendChar((*ptr++));
 return len;
}

Then I am trying to print out all values in the array:

 int print_array[1024];
 for(int i=0; i<1024; i++){
	 print_array[i] = i;
 }
 printf("Hello World!\n");
 //Print out array values
 for(int i=0; i<1024; i++){
	 printf("%d, \n", i);
	 HAL_Delay(5);
 }
 HAL_Delay(1000);
 //Print some more to make sure all data is finished printing
 for(int i=0; i<2; i++){
	 printf("Hello World\n");
	 HAL_Delay(5);
 }
 HAL_Delay(100);
 
 while(1);

But the result I get in the SWV ITM Data Console will only be consisting around 900 numbers instead of 1024 numbers. And the amount of number is fluctuating as well.

I am wondering why this happened, and whether there is any way to avoid it?

Thank you very much!