Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By Gigel
#39440 Hello,

Is it possible to program and debug ESP8266 with JLink ( https://www.segger.com/jlink-debug-probes.html ) attached via JTAG or SWD pins?
Has anyone succeeded to do so, and if yes, could you please provide details of your setup (signals wiring, debug method, development environment)?

I am using MS Visual Studio and GDB for coding and debugging via serial port, but I would like to use OpenOCD or XtensaOCD with JLink and have the serial port pins used by my application.

I am using Sparkfun Thing board ( https://cdn.sparkfun.com/datasheets/Wir ... _Thing.pdf ) for development, and I can access all the necessary JTAG/SWD signals.

Here are my wiring details from JLink ARM-20 pin interface ( http://m.eet.com/media/1073686/JTAG_101_fig3.jpg ) to my Sparkfun Thing board:

JLink GND pin 4 <==> ESP8266 GND
JLink TDI pin 5 <==> ESP8266 MTDI/SPIQ/GPIO12
JLink TMS pin 7 <==> ESP8266 MTMS/SPICLK/GPIO14
JLink TCK pin 11 <==> ESP8266 MTCK/SPID/GPIO13
JLink TDO pin 13 <==> ESP8266 MTDO/SPICS/GPIO15 (after removing R17 pull-down)
JLink RSTB pin 15 or TRST pin 3 <==> ESP8266 EXT_RSTB/DTR/RESET

Regards,
G