Connection Between JLink EDU and Nrf51822

[BK]

Hi, I used to use an imitated Jlink debugger to program/debug my target board(one Nrf51822 on it) There are pins connection between them,it works just fine.

Now I purchase a new Jlink EDU which is new to me. So my question is , in order to make Jlink EDU works with my target board,

(1)is VTref(on Jlink EDU) pin connection between Vdd of the nrf51822 a must?

(2)since the Vdd pin(on my board) connection is directly to Vdd of nrf51822 , therefore I can not directly connect 5v-supply of Jlink EDU to the Vcc(since nrf51822 works on 3v around), right?

[bjorn-spockeli]

Hi BK,

Q1: Yes, in order to program the nRF51822( or any Cortex-M0 for that matter) you will need to connect SWCLK, SWDIO, GND and VTref (Target reference voltage). VTref must be connected to VDD on the nRF51822 device.

Q2: Correct, do not connect the 5V supply from the JLink EDU to your nRF51822. You need to power you nRF51822 device from an external 1.8-3.6V supply.

[BK]

Hi BS, Thank you so much for your answer! : )