Hi,

We have been using the J-Link-OB-SAM3U128 on the Nordic NR51-DK (pca10028) from some time now. We've always programmed our targets with the easy to use drag-and-drop feature.
Our target is a NRF51422_QFAC (the same as the NRF51-DK).

Recently we moved to a J-Link Base and execute the following script to update our targets with JLinkExe:


This loads our hex file into the target, NORMAL resets the MCU and sets to cpu to a running state.

This looks pretty simple but we have recently come across a major issue.
When programmed with the script above the MCU stays in a high current consumption after disconnecting the programmer. We’ve measured around 1.2mA continuous current. When programmed through drag-and-drop, our consumption is normal which is around 10uA.
The high current consumption disappears after removing the power to the MCU, waiting some time and reapplying the power.
It seems like something in the MCU stays active after programming our target.

My question is: what does the drag-and-drop feature do apart from target programming, resetting and go?

It seems like the SWD interface stays active. For the NRF51 the reset pin is shared with the SWDIO. Trying to hard reset the target with the reset pin fails when the device current consumption is high. This might be because the SWD interface is still active. Hard resetting the target when the device is operating normally works as expected.
Is there a way to stop the SWD interface on the target MCU? Seems like the drag-and-drop feature has a way to do this.

Hi Nino,

Thank you for your response.
We're using the following setup:
- Mac OS high sierra
- J-Link Software and Documentation Pack v6.32f (also tried v6.32)

Tested on the following programmers:
Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 12 2018 16:05:20
Hardware: V1.00
And:
Firmware: J-Link V10 compiled Apr 20 2018 16:47:09
Hardware: V10.10

I've tested it with an example application from the nordic SDK:
nRF5_SDK_11.0.0_89a8197/examples/ble_peripheral/ble_app_beacon
I've attached a version for the PCA10028: ble_app_beacon_s130_pca10028.hex.zip

Result with drag-and-drop:


Result with scripting:



Also with our own application after programming:




Very strange behaviour, it seems to be related with SWD that keeps being active.

Well... I've found the solution: devzone.nordicsemi.com/f/nordi…equivalent-using-jlinkexe
It is a bit of an ugly hack to switch to JTAG and use the TMS and TCK as toggle pins to initiate a reset.
Is there a better way to accomplish this?

EDIT:
This is mostly a ugly hack because of when switching to JTAG, JLink tries to connect to the nrf51422_xxac target which fails:


Is there a way to disconnect from the target?
When I restart JLinkExe and execute "si 0" and "tck0" it works fine because it isn't connected to any target.