My nrf52840 can't boot up after power on,unless it was connected to JLINKRTTVIEW

[melancholyl]

It's strange,

My nrf52840 can't boot up after power on,unless it was connected to JLINKRTTVIEW,

If I disconnected the JLINKRTTVIEW, the device will stop running,
Connect again and it will start running again.

00> [01:58:53.135,620] <err> sx12xx_common:  TX DONE!
00> [01:58:53.935,699] <inf> lora_send: Data sent!
00> [01:58:54.142,517] <err> sx12xx_common:  TX DONE!

(Connection lost)  //disconnect and connect to JLINKRTTVIEW and device reboot agagin
00> *** Booting Zephyr OS build v2.3.0-rc1-ncs1-1446-g26216d1f7e09  ***
00>  
00> [00:00:00.039,184] <inf> lora_send: BIND PA
00> [00:00:00.039,215] <inf> lora_send: BIND PA SUCCESS!

[Vidar Berg]

Hello,

It shouldn't be necessary, but please try to disable logging over RTT and see if it still will not boot. You may also try to run "nrfjprog --readregs" to read out the Program counter (PC) register and see where the program gets stuck.

[melancholyl]

Hi,

If I disable logging over RTT,SOC will not run even I connected it to RTT Viewer

nrfjprog --readregs:

R0:   0x00000000
R1:   0x00000001
R2:   0x00001FBC
R3:   0x00000000
R4:   0x000063D1
R5:   0x20000D64
R6:   0x00000000
R7:   0x00000000
R8:   0x00000000
R9:   0x00000000
R10:  0x00000000
R11:  0x00000000
R12:  0xEE532F48
SP:   0x20001B28
LR:   0x00006F3D
PC:   0x00004296
xPSR: 0x61000000
MSP:  0x20002338
PSP:  0x20001B28

[melancholyl]

Hi,I don't know how to check this address,

BTW,the same program runs normally on nrf52840dk (on-board JLINK), and now the issue is with our mass-produced SOC

[melancholyl]

Hi,I found similar issue :nrf51-wont-run-without-debugger

this may also be related to the state of SWDIO

[Vidar Berg]

Interesting that it works fine on the 52840 DK. Does all of your custom board fail like this, or are the some that work? Also, does your board include the DCDC filtering and crystal as shown in the reference design below or not?

[melancholyl]

all boards failed,and this shouldn't be a HW design issue,some program work normal,

I consulted the zephyr OS community,here is their response:

Looks like you may be locking up due to some side effect of debug power not being properly disabled. This is a known issue in nrfjprog

Can we solve this problem , our product is blocked due to this.

[Vidar Berg]

I am not saying it has to be a HW issue, it could be that the FW is not correctly configured for your HW configuration. The parts I circled around are optional and may have been omitted in your design, which is fine as long as the FW doesn't rely on them.

melancholyl said:

Looks like you may be locking up due to some side effect of debug power not being properly disabled.

The problem should go away after a power-cycle if this is the case.

[melancholyl]

Thanks for your reply,can please help to check this?

[Vidar Berg]

Thanks. So it's important that the DCDC (DCDCEN) is not enabled in your FW since the optional DCDC inductors are not mounted on your board.  Do you know if the project is built with the DCDC disabled? If you are unsure you can verify by reading the memory with nrfjprog: "nrfjprog --memrd 0x40000578"

DCDC config option:

CONFIG_BOARD_ENABLE_DCDC=n

[melancholyl]

Thanks so much,after I disabled DCDC,issue was fixed

[Vidar Berg]

Thanks for reporting back. I'm glad to hear that it solved the problem.