Connecting the JTAG reset signal

[roman1]

Posted on August 26, 2013 at 15:47

Hi there

I'm still a bit confused about whether I have to connect the nRESET pin of the 10-pin Cortex Debug Connector to the NRST or the NJTRST pin of the STM32 in case of both JTAG and SWD connection. Could anyone tell?Regards,Roman #jtag

[Tesla DeLorean]

Posted on August 26, 2013 at 16:13

NRST/NRESET is the PROCESSOR RESET, this is what you want.

NJTRST is not on this connector. If you need a full JTAG interface, say for boundary scan, you might want to check if you want all the signals on a different connector.

[jpeacock2399]

Posted on August 26, 2013 at 21:55

Segger (the J-Link vendor) recommends using JNTRST (the JTAG reset) on pin 10, with an option to connect NRST (procesor reset)  to pin 9.  I use this on an STM32F405 motor controller and it is working with GDB/Segger J-Link/Segger 10 pin adapter combination.

  Jack Peacock

[Tesla DeLorean]

Posted on August 26, 2013 at 22:39

The use of NRST is however far more common, and viable with J-Link and U-Link. I've reviewed half a dozen schematics and can't see anyone using NJTRST, either on the boards, or converter boards.