J-link not find device(Info: Could not measure total IR len. TDO is constant high.)

[steven]

Dear all: Now,i have issue ,i can't fund device.(i have sure the hardware is OK) i think it is program overwrite the J-TAG register(TDO)? but i may not sure. have any experience about this error?

i try run J-Link commander to clear ,but

J-Link> r Info: Could not measure total IR len. TDO is constant high. Reset delay: 0 ms Reset type UNKNOWN: ??? Info: Could not measure total IR len. TDO is constant high. J-Link>r

****** Error: TCK (pin 9) low, but should be high. Please check target hardware. Reset delay: 0 ms Reset type UNKNOWN: ???

and i exe nrfjprog --recover to

it get C:\Users\steven>nrfjprog --recover Applying pin reset if debugger is not active. System off disabled until pin reset or power on reset is done. Halting device. ERROR: Cannot connect to the nRF51 device.

the nRFgo studio is also not found any device .(In the boot of the moment, nRFgo maybe detect the device) read back protected or not found device.

[Ole Morten]

To answer the original question here, it seems that the J-Link Lite for some reason can't find the nRF51822. This can be caused by a number of things, for example:

1. The nRF51822 being in system off (in this case, you should still be able to make things work by doing a recover, so this is most likely not the case here.)
2. The connector being wrongly connected (i.e. turned 180 degrees or similar).
3. The VTG of the connector not being connected to the nRF51822's VCC.
4. The VCC of the nRF51822 being outside of what's supported by the J-Link Lite. The J-Link Lite can only program devices running on 3.3 V. The voltage of the nRFgo motherboard can be set in nRFgo Studio. 5a. If you use version 1.0 of the Evaluation Kit, the jumpers on P8 either not being mounted or turned 90 degrees. 5b. If you use version 2.0 of the Evaluation Kit, the J-Link OB switch being off.

Could any of these be the problem here?

[Jim]

Ah, I didn't change those file names, so it looks like they got recreated automatically with default settings.

Next time I'll try to rename those files, too.

[Shane]

I had exactly the same problem this morning with a J-link lite.

I am working on a project that is based on the ble_app_hrs code. Copied it over and just renamed the file names to my project. Everything was working fine over the last 3 weeks until this morning when I got the "TDO constant high" error. Untouched sample projects compiled and downloaded fine, but mine would not. I moved the Parallels VM on which I had the Keil environment running, but have no idea why that would cause a problem.

I have been keeping all projects under SVN, and I saw only three modified project config files that could be the culprits:

XXX(256k).dep, XXX.uvgui.Administrator XXX.uvopt.

I reverted all of them to my last working revision and the J-link lite worked fine. I tried reverting them one at a time to see if the problem was isolated in a single file and never could get it working.

In the attachment, the "Work" directory are those which download fine while the "Do Not Work" are those that don't. Hopefully they may help someone and shorten what looks to be a painful process.

RSL-Keil project files..zip

[Paul]

I got the same problem today. Luckly it didn't take me too long to find out this "copy/paste" issue. Working on it right now to see if any luck to "fix" the copied folder. Otherwise I will create a new project. :-D

[Paul]

This is what I did to solve the problem:

Go to Cortex Jlink/Jtrace target driver setup.

In Debug Tab: Make sure the Port is set to SW, NOT JTAG. (Sometime copy/paste project will get this setting switch to JTAG).

In Flash Download Tab: Make sure nRF51xxx is selected in the programming algorithm.

After these two step. the TDO high problem is gone.