Thank you both for the advice. Im going to convert over to RMW GPIO_BSRR, and I think it makes sense to rework everything to pass parameters via the function call. In that case, the parameters go into R0-R4? I'm trying out several methods for my o...

I think my problem is how to get the external variable (or its address) into an assembly register at all, or to find out its name if it exists. For example if my external variable is PIN_LOCATION, I get an error when I do something like thisLDR R3,=...

Thanks for responding Clive. I have zero experience in assembly, so apologies in advance. Here is part of the code I have in the assembly script, toggling a gpio pin. I want to tell the assembly snippet to choose between different pins by turning ...

Much appreciated TDK! I missed that note trying to find something about it in the data sheet.