J-link can't connect to the NRF52810 in high frequency

RE: J-link can't connect to the NRF52810 in high frequency

Håkon Alseth — Thu, 28 May 2020 07:30:31 GMT

Hi,

[quote user="Atec Electronique"]Moreover the problem came after several perfect connections, so I'm not sure that it comes from that.[/quote]

The schematic looks good wrt. SWD connections.

As a side-note: I would recommend that you look into the components on the ANT pins, as it is required that you have a shunt capacitor + a series resistor to provide a 50 ohm output for antenna connection: https://infocenter.nordicsemi.com/topic/ps_nrf52810/ref_circuitry.html?cp=4_5_0_6_2

the short of the series inductor L4 looks a bit strange.

For the unresponsiveness over SWD; Could it be that your firmware asserts? If it asserts early on in the boot-up, it is hard to erase/recover the chip. Could you try running this batch script to see if it recovers the device after a while? https://devzone.nordicsemi.com/f/nordic-q-a/45078/nrf52832-not-connected-anymore-after-first-trying-to-debug-keil/177579#177579

I've seen that if you power the nRF on/off while keeping the nrfjprog-loop active, it is easier to recover.

Kind regards,

Håkon

RE: J-link can't connect to the NRF52810 in high frequency

Atec Electronique — Wed, 27 May 2020 15:53:17 GMT

Thank you for your quick answer.

The thing is that we are directly plug into the chip, there are no components between the Jlink and the SWDCLK line and the SWDIO line, here's the schematic :

Moreover the problem came after several perfect connections, so I'm not sure that it comes from that.

Any other ideas ?

RE: J-link can't connect to the NRF52810 in high frequency

Håkon Alseth — Wed, 27 May 2020 12:47:02 GMT

Hi,

Is there any resistors, caps, or other components that are loading the SWDCLK / SWDIO lines? Given that you can read out if you go to a lower frequency can be due to a capacitor on the line. If you are able to connect via JLink (on very low speed), you can try to run the sequence to erase the chip and see if this helps:

https://github.com/ssfrr/nrfjprog.sh/blob/master/nrfjprog.sh#L61-L70

If the device is asserting early in the program, where the default assert behavior is to do a system reset, it is hard to recover the device, as the chip is constantly booting up and resetting.

Kind regards,

Håkon