Hi,

i bought a J-Link EDU to do some lowlevel debugging and software development on RISC-V.

I have a Sipeed Longan Nano.

I followed this wiki article to connect my J-Link:
wiki.segger.com/SiPeed_Longan_Nano
segger.com/products/debug-prob…gy/interface-description/

I connected the J-Link via USB with my PC.
I connected the Sipeed via UsB with my PC.
Then i connected the JTAG cable with the J-Link.

Starting J-Link Commander shows VTref=0.000 and the 'connect' procedure fails -> "Cannot connect to target.".

I tried it on Linux and Windows. On Windows i get the same behaviour.

I was following the advice described here:
wiki.segger.com/J-Link_cannot_connect_to_the_CPU



I tried testing the VTref detection by attaching an external PowerSupply with 3.3V directly to the J-Link without
the JTAG cable. VTref was still Zero. I used a multimeter to test the JTAG Cable itself, it seems to be OK.
I also measured VTref (Pin 1) and Ground (Pin 4) on the J-Link with a multimeter. The result was 0.04 mV.

I don't know what to do or what else to test. Any ideas?

P.S. This is my Second J-Link, the first one was a v11 and had the same problem.

OK, i found my mistake.
segger.com/fileadmin/images/pr…scription/181129_JTAG.svg

I was looking at the picture and i was using it to connect my cables to the JTAG cable. But this picture
shows the pinout of J-Link device and not the cable.... everything works now.

Thanks anyway.