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JTAG connection to STM32F407 with ST-Link V2 is not working

Question asked by Patrick Morwald on Mar 22, 2018
Latest reply on Mar 29, 2018 by Patrick Morwald

I am trying to debug my STM32F407 based board with the ST-LinkV2 adapter. It works fine when i use SWD, but i cannot get a JTAG connection.


Here is the error i get when trying to connect via JTAG:


Wrong device detected
Open On-Chip Debugger 0.10.0-dev-00007-g58350bc-dirty (2018-01-08-12:20)
Licensed under GNU GPL v2
For bug reports, read
srst_only separate srst_nogate srst_open_drain connect_assert_srst
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
adapter_nsrst_delay: 100
adapter speed: 1125 kHz
Info : tcl server disabled
Info : telnet server disabled
Info : clock speed 1125 kHz
Info : STLINK v2 JTAG v29 API v2 SWIM v7 VID 0x0483 PID 0x3748
Info : vid/pid are not identical: 0x0483/0x374B 0x0483/0x3748
Info : using stlink api v2
Info : Target voltage: 3.212598
Error: init mode failed (unable to connect to the target)
in procedure 'init'
in procedure 'ocd_bouncer'


I connected my ST-LinkV2 to the STM32F407VGTx (LQFP100) in the following way:


ST-Link P1 (VAPP) -> STM32 VDD

ST-Link P6 (GND) -> STM32 GND

ST-Link P5 (JTDO) -> STM32 PA15 (JTDI)

ST-Link P13 (JTDI) -> STM32 PB3 (JTDO)

ST-Link P7 (JTMS) -> STM32 PA13 (JTMS)

ST-Link P9 (JTCK) -> STM32 PA14 (JTCK)


But i cannot connect to my processor, neither with St-Link utility nor can i start a debug session with SW4STM32 IDE.

I use 1,25 MHz JTAG since i think thats the maximum the St-Link V2 supports?


Please help.