Forum : ARM
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May 14, 2009 - 9:59am
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Dear Raisonance, I am experiencing a problem with the speed of the JTAG clock with RLink and RFlasher7. We have just moved to the final PCB for an STM32 project and can no longer program or debug the board. Neither JTAG or SWD no longer work - incorrect ID codes are read when trying to connect to the target. It looks as if it is a dynamic problem as the miniature board has to be programmed over a cable to a JTAG adaptor. Even though I change the JTAG clock setting in RFlasher7 the JTCLK is still toggling at nearly 3MHz for JTAG and at approximately 2MHz with SWD. A much slower JTCLK is acceptable for our application and I am sure the (unavoidable) cable capacitance is having an effect. Is there a solution for this issue ? It is now very urgent that we resolve it. Thanks in advance. |
Hi
I suggest you first verify you are using the latest version of our softwares from:
http://www.mcu-raisonance.com/mcu_downloads.html
If it does not solve your issue please answer to the questions from:
http://raisonance-forum.xsalto.com/viewtopic.php?id=2231
And send the answer to
This should helps us treating your issue faster.
Regards,
Matloub
Hi,
It is normal that the SWD clock speed cannot be lowered, as the SWD part of the Cortex is not synchronized with the CPU's clock, and the speed option is there for CPUs with slow clocks, not for long wires.
You could have a chance to work around your problem by using JTAG and slowing the clock down, but I just saw that there is a bug in the recent versions of our software that makes the clock speed option ignored.
Please download this file and copy the four files in it to your \bin directory:
ftp://www.raisonance.com/temp/test_090514_fix_Cortex_JTAGClockSpeed.zip
(First, make sure you are using the very latest version of the Ride and ARM kits, available for download on our website. see Matloub's post above)
Then you should be able to slow your JTAG clock down to around 400KHz.
Please let me know how it goes.
Note also that the design of your adapter/cable can have a big impact on these issues. Try to keep it as short as you can, and if possible keep the one-ground-out-of-two-wires scheme of the original ARM JTAG 20-pts connector/cable.
Best Regards,
Vincent
Dear Vincent,
Thank you very much for the excellent and prompt response.
The new DLLs work fine. It is now possible to adjust the JTAG clock speed within RFlasher which is exactly what was needed to compensate for the capacitive loading effect of the programming cable that we need to use. At the original clock speed (> 3MHz) the programming was unreliable even though I eventually managed to get it to work by careful termination of the signal wires.
Once again, many thanks for your help.