nrf_serial UART on nRF52840 sdk 15

[mtfurlan_t]

I would like to use both UARTs.

I'm trying to run the given example with SDK patch from https://devzone.nordicsemi.com/f/nordic-q-a/25173/nrf52840-uart1-not-working-in-sdk-14/99170#99170

What happens is that roughly a few hundred ms after it prints "Hello nrf_serial!" it somehow goes into the default IRQ handler at modules/nrfx/mdk/gcc_startup_nrf52840.S:358 which is just an infinite loop.

Before it goes there, it will read successfully.

I've commented out everything for uart 1, just to simplify the example.

I can't figured out how it gets to the default IRQ handler.

my main.c: http://ix.io/1dsX

I'm using the NRF52840 preview development kit and nRF5_SDK_15.0.0_a53641a

The makefile and linker I'm using are from examples/peripheral/uart/ and I'm using gcc-arm-none-eabi-7-2017-q4-major, (GNU Tools for Arm Embedded Processors 7-2017-q4-major) 7.2.1 20170904 (release) [ARM/embedded-7-branch revision 255204]

Makefile has a few additions in order to have the necessary dependancies, but that should all be fine.

Diff: http://ix.io/1dsH

[Vidar Berg]

Hi,

It's possible that you're seeing this bug if you have enabled link time optimization (-flto) : https://bugs.launchpad.net/gcc-arm-embedded/+bug/1747966 . Please try the GCC ARM Embedded 6.3 2017-q2-update release and see if you get the same result. This is the release we used for testing and validation of SDK 15.0.0 (stated in release notes). 

 

[mtfurlan_t]

I do not have -flto enabled.

I tried switching to 6.3 2017-q2-update but did not see any difference.

[mtfurlan_t]

So I tried again from scratch, and it works. I clearly touched something I shouldn't have and didn't notice.
Sorry about the confusion.

Once again, the issue is user error.

[Vidar Berg]

Thanks for the update. '10' is the POWER_CLOCK_IRQn so it seems that the problem was related to the clock configuration, not UARTE.  

[mtfurlan_t]

Fair enough, I was noticing that it wouldn't crash if I disabled the app timer, so I thought it was something there.

Where is the documentation on the ISR numbers?

[Vidar Berg]

You can find the ARM documentation of the interrupt status register here, and the ISR numbers used on nrf52840 can be found in the nrf52840.h header (\modules\nrfx\mdk).

Notice that processor exceptions starts from -15 so POWER_CLOCK_IRQn corresponds to 16 in the interrupt status register.

[mtfurlan_t]

Many thanks.