PSOC6 Serial Wire Viewer

You can always use an UART component in your firmware to sent out debugging messages. PSoC 6 kit has an embedded USB to UART, so you can use PC Terminal to visualize debug messages sent by your firmware.

If you check core_cm4.h file, there are three system call functions:

- ITM_SendChar

- ITM_ReceiveChar

- ITM_CheckChar

They use the ITM channel to send/receive messages.

How can one listen to the data send on the ITM channel?

To read the debug printf messages through SWV pin, I did the following:

1. Changed the Debug Select to SWD+SWV in one of the PSoC 6 MCU project and built it.

2. Exported the project to Keil uVision 5 by following the steps provided in Creating µVision Projects for PSoC 6 of the PSoC Creator Help document.

3. Redirected the STDERR, STDIN, STDOUT to ITM in Keil uVision IDE's is Run-time Environment (steps are available in the uVision's User Guide).

4. Connected the ULINKpro debugger to J11 header CY8CKIT-062-BLE board. Rebuilt the project in uVision and started the debug session.

I was successfully able to see the message steam in Debug (printf) Viewer window of the uVision IDE.

Although I haven't used the MiniProg3 here, thought of sharing this info, if you are interested to try.

Did you manage to use the SWO pin? A have the same issue with a Psoc6. No activity on SWO pin.

I configure and enable the ITM using the code below

// Debug Exception Monitor and Control register

#define DEMCR   (*((unsigned long *) 0xe000edfc))

#define TRCENA  0x01000000  // enable trace

// Stimulus Port registers

#define ITM_STIM0 (*((unsigned long *) 0xe0000000))

#define ITM_STIM1 (*((unsigned long *) 0xe0000004))

#define ITM_STIM2 (*((unsigned long *) 0xe0000008))

#define ITM_STIM3 (*((unsigned long *) 0xe000000c))

// Trace enable registers

#define ITM_TER   (*((unsigned long *) 0xe0000e00))

// Privilege register: registers that can be accessed by unprivileged code

#define ITM_TPR   (*((unsigned long *) 0xe0000e40))

// Trace Control register

#define ITM_TCR   (*((unsigned long *) 0xe0000e80))

// Lock Access register

#define ITM_LAR   (*((unsigned long *) 0xe0000fb0))

// unlock value

#define ITM_LAR_ACCESS  0xc5acce55

void ITM_init(void)

{

    ITM_LAR = ITM_LAR_ACCESS; // unlock

    ITM_TCR = 0x1;            // global enable for ITM

    ITM_TPR = 0x1;            // first 8 stim registers have unpriv access

    ITM_TER = 0xf;            // enable 4 stim ports

    DEMCR = TRCENA;           // global enable DWT and ITM

}

and the implimation of fputc()

int32_t ITM_SendChar (int32_t ch) {

  if ((ITM_TCR & ITM_TCR_ITMENA_Msk) && /* ITM enabled */

      (ITM_TER & (1UL << 0)        )) { /* ITM Port #0 enabled */

    while (ITM_PORT0_U32 == 0);

    ITM_PORT0_U8 = (uint8_t)ch;

  }

  return (ch);

}

The ITM_PORT0_U32 is always 0 so never return from the while (ITM_PORT0_U32 == 0);