Search Results

Thanks, I'll take a look.

Thanks, but that seems to be talking about some HW thing called 'VCOM'. What I mean is that I want to take the SWO data stream from the JLink SW and present it internally within the PC as a COM port, so pure software, no additional HW involved. It would be something that incorporated the JLink DLL and created a virtual COM port, a bit like a TAP/TUN interface does for network interfaces. Do you publish the interfaces that the Jlink DLL offers to permit this? Rob

Hi there. I have a PC application which expects to connect to an embedded target's serial port and interpret the stream of serial data received from the target. Now I would like to connect it to an embedded target which is, instead, sending its output via SWO. in other words, I'd like the SWO stream from the target to appear as a virtual COM port on the PC. Do the JLink tools offer an interface through which I can do this? I would be happy to incorporate a JLink DLL and, given an API into the DL…

Oh, no, don't worry about this, it was a bug in the patch in the target code, all is working as intended.

Having got SWO viewer working sweetly, I have one additional question: what does jLinkSWOViewerCL (V632a) need to form a line ending? I ask because I am sending a string with a CR and LF ending but in SWO Viewer the CR and LF characters effectively disappear. So in jLinkSWOViewerCL, sending printf("Hello world %d.\r\n"), x) in a loop, I get: Hello world 0.Hello world 1.Hello world 2. ...while in GDB (which I think is interpreting both CR and LF as line endings) I get: Hello world 0. Hello world …

Yes, that's definitely it, you're off the hook: writing four characters into the 4 bytes of the ITM register at a time does the trick. I've raised this with mbed-os to get their implementation changed to be friendly to this sort of client. Many thanks!

Sorry, posted at the same time. Many thanks for checking this. I am using V632a and the target is a commercial u-blox NINA-B1 module on its evaluation board. I think there's something in the above: how does jLinkSWOViewerCL interpret the four bytes coming out of the SWO output?

I've now removed the TRACECONFIG, PIN_CNF (for pin 18) and TPI->ACPR lines, so the entire ITM init, from the code but the result remains the same as above (just the initial letter of my printf() appears); I suppose this is to be expected as starting jLinkSWOViewerCL with the command-line: jLinkSWOViewerCL -device NRF52832_XXAA ...will likely overwrite the boot settings anyway. Interestingly, if I leave the ITM initialisation in my code and then use GDB to download the code and view the SWO outpu…

Unfortunately I'm using software which always configures the ITM; Nordic's NRF52832 target in mbed-os does this at boot. I will try hacking it out and see if that helps but it's not ideal as I then can't use the master mbed-os code directly: surely I should be able to tell J-Link what I've configured as the SWO clock frequency and it will just do it? That's certainly what the -swofreq command-line option looks as though it should be for.

FYI, this is the closest I have got. With the command-line below my prints of "Hello World.\n" every second come out as "H" (i.e. the initial letter) followed by nothing else every second, so I don't think jLinkSWOViewerCL has listened to my -cpufreq (and it also says 0 kHz in the command output). jLinkSWOViewerCL -cpufreq 64000000 -swofreq 4000000 -device NRF52832_XXAA ************************************************************ * SEGGER Microcontroller GmbH * * Solutions for real time microcon…

Hi there. I am using an NRF52832 target and have configuration code in my target image which sets up the SWO port to run at 4 MHz (CPU @ 64 MHz). I would like to use my Segger J-Link Base and the jLinkSWOViewerCL command-line application (JLink_V632a) to view the SWO output from the board: I do not want jLinkSWOViewerCL to configure my target hardware at all, I just want it to view the SWO output from the target HW as I have already configured it. I have tried various combinations of command lin…

Hi there. I'm trying to track down a problem with code optimisation which results in my M0 target crashing at boot. On this target platform I have to load code onto the target (via the SEGGER J-Link box) using a third party executable (as hashes are written as well as the code). Unfortunately this third party application resets the target after download. As soon as the target is running with this bad code that I want to debug, J-Link can no longer connect to it so I am unable to see what's going…