Problem with USB DFU when RTT is disconnected

RE: Problem with USB DFU when RTT is disconnected

Hung Bui — Wed, 15 Nov 2017 09:58:06 GMT

Hi Artak,

I don't think there will be clean way to detect the chip. But all v0.9.3 should have the fix. Also the production chip shouldn't have this problem.

RE: Problem with USB DFU when RTT is disconnected

Artak — Tue, 14 Nov 2017 20:35:57 GMT

If my understanding is correct the chip on 0.9.3 board differs from the one on 0.9.2 board. But their marking is identical. So How I can check that the chip I'm going to solder on my board has that USB issue fixed?. IS there any revision number or something similar which helps to distinguish the fixed chips form older versions ?

RE: Problem with USB DFU when RTT is disconnected

Hung Bui — Tue, 14 Nov 2017 15:24:27 GMT

Hi Artak,

I just got some more information from our team, that the 0.9.3 version actually fixed some issue with the USB on the chip. Some calibration data has been updated. No change on PCB. So it's clearly not something to do with the PCB and you can continue your development with your 0.9.3 board and designing of your PCB.

RE: Problem with USB DFU when RTT is disconnected

Artak — Tue, 14 Nov 2017 04:29:51 GMT

I am looking at nRF52840 marking on both 0.9.2 and 0.9.3 and both have the same date code 1716AK. Do the packages actually contain different revisions of silicon?. If Yes then how I can check the silicon revision? maybe through J-Link ?

RE: Problem with USB DFU when RTT is disconnected

Hung Bui — Mon, 13 Nov 2017 15:55:42 GMT

We are not clear about that at the moment, but it's less likely an PCB issue, more like a silicon hardware or could be timing/driver issue.

RE: Problem with USB DFU when RTT is disconnected

Artak — Fri, 10 Nov 2017 15:55:39 GMT

Hi Hung,

No there is no issue on 0.9.3 board. I'm just curious whether this issue is related to board schematic or it is coming from silicon of nrf52840 earlier version. I need the info in order to avoid the same situation on my own design.

RE: Problem with USB DFU when RTT is disconnected

Hung Bui — Fri, 10 Nov 2017 11:27:30 GMT

Hi Artak, We noticed the issue and reproduced here. We are looking at the problem. It could be hardware related. Please let us know if you see the issue on 0.9.3

RE: Problem with USB DFU when RTT is disconnected

Artak — Thu, 09 Nov 2017 05:53:48 GMT

Update: It looks the issue is resolved in 0.9.3 version of PDK board.

Could you please let me know whether it is a board design issue or an issue with older version of nRF52840?

RE: Problem with USB DFU when RTT is disconnected

Artak — Tue, 07 Nov 2017 18:38:08 GMT

Update: It looks the code stucks at WFE in wait_for_event function (file nrf_dfu.c) static void wait_for_event() { while (true) { app_sched_execute(); if (!NRF_LOG_PROCESS()) { #ifdef BLE_STACK_SUPPORT_REQD
(void)sd_app_evt_wait(); #else __WFE(); #endif } } }