Hello SEGGER, greetings from Wales!

I seem to be having a spot of bother with my recently purchased J-Link mini. No matter what I have tried to do, the J-Link doesn't seem to like my Arduino Due's part, an Atmel ATSAM3X8E. The J-Link finds the correct part, but as can be seen from the trace below, it just won't commune with it, it "Cannot connect to target.", which diagnostic I get on both of the Due's USB ports.

"""
C:\Program Files (x86)\SEGGER\JLink>jlink
SEGGER J-Link Commander V6.80e (Compiled Jul 13 2020 19:01:34)
DLL version V6.80e, compiled Jul 13 2020 19:00:48


Connecting to J-Link via USB...O.K.
Firmware: J-Link EDU Mini V1 compiled Jun 9 2020 13:36:46
Hardware version: V1.00
S/N: 801021561
License(s): FlashBP, GDB
VTref=3.299V




Type "connect" to establish a target connection, '?' for help
J-Link>connect
Please specify device / core. <Default>: ATSAM3X8E
Type '?' for selection dialog
Device>
Please specify target interface:
J) JTAG (Default)
S) SWD
T) cJTAG
TIF>
Device position in JTAG chain (IRPre,DRPre) <Default>: -1,-1 => Auto-detect
JTAGConf>
Specify target interface speed [kHz]. <Default>: 4000 kHz
Speed>
Device "ATSAM3X8E" selected.




Connecting to target via JTAG
Could not measure total IR len. TDO is constant high.
Could not measure total IR len. TDO is constant high.
Could not measure total IR len. TDO is constant high.
Could not measure total IR len. TDO is constant high.
Cannot connect to target.
J-Link>
"""

Further, Atmel Studio is unhappy too, as it complains with "Error: Error connecting to device over JTAG", which is the same diagnostic reported by Studio when there is no ribbon cable between the J-Link and the target at all!

Unfortunately, I don't have any other parts/cards to test the J-Link with, so the above trace is the best I can manage, for the moment. I hope it helps.


Kind regards, Bill

Bill here, replying to my own thread... I wonder if this is a faulty ribbon cable?

I tried taking photos, but the resolution wasn't so hot. However, I have something better, the link to the images I used to wire up the Arduino Due and the J-Link mini in the first instance: embeddedcomputing.weebly.com/s…with-arduino-due8203.html ... The little red line of the ribbon cable on my setup accords with the picture at the bottom of the linked to page.

Bill

Souhail, Hi! I tried SWD, and JLink.exe complained again, "Cannot connect to target." Bill

Hello Fabian! Yes, the plugs are in their sockets in the correct manner. I thought that the cable might be the problem, when I removed it during the software testing, only to find the same diagnostics as when the cable was plugged in! I've sent off for some little ribbons, so I can attempt to close off this post later - when they arrive. I would trace through the ribbon signals, but I have no lab stuff these days. Regards, and thanks, Bill

Hello, me again. I've been trying to purchase a replacement ribbon cable for my JLink EDU mini, but don't know the ribbon cable's exact specification. I've looked on eBay, but they are chockablock with 2.54 mm pitch 10x10 ribbon cables, which are too big for the JLink mini. Does the JLink mini use 1.27 mm pitch cables I wonder? And if it does, where can I find them? Kind regards, Bill

Hi Fabian. I found a 1.27mm pitch ribbon cable on eBay, eventually. Hong Kong! Yes, I'd have thought it a common cable type too, but eBay suggests otherwise. I'll let you know how the experiment of replacing the cable goes. Regards, Bill

Hi Fabian. The new 1.27mm pitch cable came from Hong Kong, but it did not clear the problem. I still have "Could not measure total IR len. TDO is constant high." as the JLink.exe error. (The cable is connected as per embeddedcomputing.weebly.com/s…with-arduino-due8203.html - as was the case in the previous test.) If you recall, it was thought at your end that this fault was caused by a cable disconnect, a faulty cable, but I've got the same diagnostic with a second cable, which suggests a fault elsewhere, doesn't it? Bill

Connecting to target via SWD
Cannot connect to target.

Hi Fabian.

Regards from Wales. As you can see from the above, the JLink still doesn't want to play ball, even with SWD. I've looked at the pinout for the Arduino Due board, and the SWD pins have a different pitch, the JTAG female ribbon being the wrong connector for them. Indeed, the Atmel part ATSAM3X8E does support SWD, but it also supports JTAG too - your colleague is in fact correct on that point.

This is at once perplexing, and annoying, as I had to send off to Hong Kong for test ribbon cables. What to do, as the JLink seems to be JTAG native?

Bill

Hi Fabian. This is all getting a bit too complex for a simple log of messages, so I've itemised the things done so far:

. tested with JLink.exe as JTAG - "Could not measure total IR len. TDO is constant high."
. tested with JLink.exe as SWD - "Cannot connect to target."
. tested with JLink.exe disconnected - "Cannot connect to target."
. above tests with new ribbon cable - same results

What can not be tested at the moment is the functioning of the target itself. For this reason I have ordered something to test the target's SWD, to check the ARM's data paths. If that route proves to be open, and SWD works, then the J-Link mini is called into question.

I'll let you know how things go.

Bill