Can’t get SWV to work on my NUCLEO-WL55JC1

[MBaza.1]

Hello,

Apologize for the long post/question…

Using the NUCLEO-WL55JC1 board, I am trying to get SWV to redirect printf() output to the IDE console, with no luck.

I added the below code to syscalls.c and modified the _write() function to call this function. I also set the IDE to monitor port 0, and start.

//Debug Exception and Monitor Control Register base address
#define  DEMCR  *((volatile uint32_t*) 0xE000EDFCU )
// ITM register addresses
#define  ITM_STIMULUS_PORT0  *((volatile uint32_t*) 0xE0000000 )
#define  ITM_TRACE_EN  *((volatile uint32_t*) 0xE0000E00 )

void ITM_SendChar(uint8_t ch) {
	//Enable TRCENA
	DEMCR |= (1 << 24);

	//enable stimulus port 0
	ITM_TRACE_EN |= (1 << 0);

	// read FIFO status in bit [0]:
	While (!(ITM_STIMULUS_PORT0 & 1));

	//Write to ITM stimulus port0
	ITM_STIMULUS_PORT0 = ch;
}

In addition,

- I verified that \n is at the end of the printed string.

- I checked the board and there are jumpers on the T_SWDIO, T_SWCLK, and T_SWO. I assume that having the jumpers means that this is enabled.

- The MCU datasheet states (for the M4 core):

32-bit Arm® Cortex®-M4 CPU – Adaptive real-time accelerator (ART Accelerator) allowing 0-wait-state execution from flash memory, frequency up to 48 MHz, MPU and DSP instructions.

So, I set the speed to 48.0

- When I connected the board the first time and started the IDE, it popped a window asking me to approve the upgrade to STLINK/V3. Maybe this causes the issue?

I would very highly appreciate your help in resolving this and helping me get this to work.

Thanks a lot,

Motti

[AScha.3]

Hi,

1. the cpu frequency in ds is not important, you have to set the real frequency, the cpu is running in your program.

2. st-link update should not matter.

3. to send on SWV just put this at end of your main:

/* USER CODE BEGIN 4 */
int __io_putchar(int ch)
{
    ITM_SendChar(ch);
    return (ch);
}
/* USER CODE END 4 */

 -user code area- 

Thats all.

To get it running, if still problem...search here in forum "swv" and read a little...

[MBaza.1]

Thanks for your quick reply!

I am new to the STM32 family so I am asking newbe questions.

I did not understand the first item:

1. the cpu frequency in ds is not important, you have to set the real frequency, the cpu is running in your program.

What should I do about that? Where to find the data and where to insert it?

Will highly appreciate your help!

Thanks a lot!

[AScha.3]

ok..

You set the clock tree in Cube...so you (should) know, what you set the clock for cpu etc.

Maybe better you read at first, how to begin; just search the tutorials on STM , or here in forum.

And how to work with the IDE -- quick start , user manual, youtube videos (a lot ! )...