sd_flash_write() cause NRF_FAULT_ID_SD_ASSERT

[hathach]

Hi,

I have run into an issue with nrf52840 on pca10056 v1.0.0 board. The softdevice is SD v6.1.0. It seems to be a hardfault which cause a reset when I tried to call sd_flash_write(), sd_flash_page_erase() is OK though. The address and buffer is 4 byte aligned, the number of word is 1024.

Following the parameter of the callback error that Softdevice invoked

• id = 1 (NRF_FAULT_ID_SD_ASSERT)
• pc= 0x00014A3A
• info = 0x00

if SD is not enable, there will be no problems at all. Strange things is the very same code run without issue on nrf52832 S132 v6.1.0.

I am appreciated if anyone could provide a hint why SD assert at that pc location.

Thanks in advance

[Einar Thorsrud]

Hi,

I see this on my side as well. The assert indicate that the SoftDevice spends too much time writing to flash. I am not sure why though, as the API documentation states that the maximum number of words is 1024 (number of words in one flash page). I will look more into it and hopefully have more info on Monday.

[Nandi]

I also found the same issue, using s340 6.1.1. What do I have to do to use flash when enabling softdevice? This is a very serious issue for the products we are developing. The current product cannot continue to do so.

[Einar Thorsrud]

Hi Nandi,

The problem is that long writes takes longer time than what has been allocated to the flash write by the internal scheduler in the SoftDevice. Splitting long writes into multiple shorter once should be an acceptable workaround in most case. There is nothing else you need to consider, other than things like not accessing the NVMC directly when using the SoftDevice, but that is unrelated to this issue.

[Nandi]

thank you for your reply, According to the way you said, it can be solved. I have another problem here. I use the internal Flash to make a U disk. I can't call the flash write function in the usb interrupt and it will timeout.  It has been resolved when I use polling in usb intterupt .  thank