how to transmit data via SWO STM32H743

[LJack.3]

I can not start transfer via SWO to STM32H743.

Port PB3 initialized clock feed.

Initialized SWO:

*(__IO uint32_t*)(0x5C001004) |= 0x00700000; // DBGMCU_CR D3DBGCKEN D1DBGCKEN TRACECLKEN
 
 //UNLOCK FUNNEL
 *(__IO uint32_t*)(0x5C004FB0) = 0xC5ACCE55; // SWTF_LAR
 *(__IO uint32_t*)(0x5C003FB0) = 0xC5ACCE55; // SWO_LAR
 
 //SWO current output divisor register
 //This divisor value (0x000000C7) corresponds to 400Mhz
 //To change it, you can use the following rule
 // value = (CPU Freq/sw speed )-1
 *(__IO uint32_t*)(0x5C003010) = ((SystemCoreClock / 2000000) - 1); // SWO_CODR
 
 //SWO selected pin protocol register
 *(__IO uint32_t*)(0x5C0030F0) = 0x00000002; // SWO_SPPR
 
 //Enable ITM input of SWO trace funnel
 *(__IO uint32_t*)(0x5C004000) |= 0x00000001; // SWFT_CTRL
 
 // Configure GPIOB pin 3 as AF
 *(__IO uint32_t*)(0x58020400) = (*(__IO uint32_t*)(0x58020400) & 0xffffff3f) | 0x00000080;
 
 // Configure GPIOB pin 3 Speed
 *(__IO uint32_t*)(0x58020408) |= 0x00000080;
 
 // Force AF0 for GPIOB pin 3
 *(__IO uint32_t*)(0x58020420) &= 0xFFFF0FFF;
 
 uint32_t SystemCoreClock = 480000000;

include printf:

int _write ( int file, char *ptr, int len )
{
 int i = 0;
 for ( i = 0; i < len; i++ )
 ITM_SendChar ( *ptr++ );
 return len;
}

Calls when passing a message through printf (); Checked set the brepoint in _write the moment the transfer is called

I checked the PB3 leg with an oscilloscope there is no signal.

The call to _write is passed to ITM_SendChar (* ptr ++); there is.

What is the matter, I ask for help.

_________________________

Gordon Bullard & Company

[Tesla DeLorean]

The ST-LINK/V2 on the original NUCLEO-H743ZI ran at 2 MHz

The frequency on the ZI2 version with the ST-LINK/V3 ran a lot faster.

I'd probably bring up the STM32 Cube Programmer SWV Window, and change the 2000000 to 24000000 or whatever you've selected as the connection speed. It's a ratio between the MCU clock, and the SWD clock..

The familiar looking code also assumes GPIOB clock has been enabled.

[Nikita91]

In my code I have an ITM initialization:

// Configure ITM
	ITM->LAR	= 0xC5ACCE55 ;		// ITM Lock Access Register, C5ACCE55 enables more write access to Control Register 0xE00 :: 0xFFC
	ITM->TCR	= 0x00010001 ;		// ITM Trace Control Register
	ITM->TPR	= ITM_TPR_PRIVMASK_Msk ;	// ITM Trace Privilege Register. All stimulus ports
	ITM->TER	= portMask ;			// ITM Trace Enable Register. Enabled tracing on stimulus ports. One bit per stimulus port.

 ITM/SWO works only in debug mode