Hal_Atomic_Start() and Hal_Atomic_Stop(), but with error "undefined reference to `hal_atomic_start'"

[buglovebug]

hi, I am trying to use Hal_Atomic_Start() and Hal_Atomic_Stop() to imply an atomic block, in order to avoid interrupt from system when execute the atomic block, source code like below:

#include "hal_atomic.h"

atomic_t atomic = 0;

hal_atomic_start(&atomic);

setPinOutput(pin);

writePinLow(pin);

hal_atomic_end(&atomic);

but when I compile it, I got belwo error:

| c:/msys64/mingw64/bin/../lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld.exe: .build/example/matrix.o: in function `setPinOutput_writeLow':
| D:\Projects\example/matrix.c:83: undefined reference to `hal_atomic_start'
| c:/msys64/mingw64/bin/../lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld.exe: D:\Projects\example/matrix.c:85: undefined reference to `hal_atomic_end'

I check whole SDK, do not find implimentation of Hal_Atomic_Start() and Hal_Atomic_Stop().

Question is that why I got the above error? how to imply Atomic block in NRF5?

[Vidar Berg]

Hi,

These hal_atomic_* functions are not available outside of the IEEE 802.15.4 MAC library. You can use the CRITICAL_REGION_ENTER and CRITICAL_REGION_EXIT macros instead.

But I don't see why you would need a critical section for configuring an output? You can configure the pin state first if you are worried about an interrupt between setPinOutput() and writePinLow():

writePinLow(pin);

setPinOutput(pin);

Best regards,

Vidar

[buglovebug]

thanks a lot for your detailed explain, the code is just an example, just want to know how to imply Atomic Block in NRF5.

But thanks again for your rapid reply.