VTARGET showing 0 value while running JLinkExe on linux

[akhil]

hi, I am very new to ble and I am trying to download softdevice S110 to my Yunjia NRF51822 board. I am using J LINK connected to my linux PC to download the softdevice to the board. I have used following pins of the board for connection with the J Link : SWDIO, SWCLK, GND, VCC, TREF; out of which except for VCC which is connected to the 3.3v, all others are connection between Yunjia NRF51822 board and J Link(including a common ground). Following is the output obtained : Screenshot from 2015-07-10 18:12:29.png

as can be seen, the VTARGET comes out to be 0 and it is not displaying the details of the connected target device. Is it issue with my Yunjia NRF51822 board or some settings on the JLinkExe. I hope my connections are fine. Please correct me if any JLinkExe configuration fault or connection fault from my side.

following is the connections that I have used :

for J Link, pins are as follows :

for nrf8122, pins are as follows:

I have connected the VDD pin from nrf51822 to VTref pin on J Link.

Its my first post on this forum and I look forward to it. :) Thank you and regards, in advance.connection

[FormerMember]

Welcome. :) The Vref from JLink should be connected to the VDD of nrf51822, which is 3.3 V. Then JLink will now know that the device that it is programming is powered. Where are you connecting Vref to now (I guess this is what you mean by TREF)?

[Stian Røed Hafskjold]

Where did you connect the VREF? Narendra's answer below is correct. You can connect this to VDD

[akhil]

hi PrithviRaj, for you convenience, I have edited the question and included the connections that I have used for the Vref. I hope there is no issue with current connection.

[Stian Røed Hafskjold]

Looks good! So, is it working now?

[FormerMember]

Working now? Can you check if VDD and Vref are at 3.3V with respect to ground?