[ARM] is it reasonable to learn arm assembly

Hello,
I writing avr and pic codes by assembly.
Todays I trying to learn arm with assembly language
Is it reasonable to learn arm by assembly?
I don't know what source I need to start.
Please recommend me a good source to learning how to write code in stm32 cortex-m3 by assembly.
Thanks

Not reasonable. It is already C optimized.

Hello!

I don't think there can be any definite reply to that kind of question. But I think it doesn't
make much sense today to program in assembly.
- There is absolutely nothing that you can do in assembly and cannot do in C
- Today's compilers are so optimized that it becomes always more difficult to compete with
a compiler when it's time to generate your code.
- Assembly is not portable. At least less portable than C.

My approach would be as follows:
- Write everything in C / C++
- When you want to really improve a highly repetitive routine, then compile it, open a disassembler
window and check what it does. At this point, in case you want to improve a particular section,
you can copy the assembler code, replace your C code with the _asm() routine, and modify the
texte in the asm routine.
NB: I don't do it often, so I'm not sure of the _asm() syntax.

Dora

ARM is RTOS oriented architecture. How do you planning to use RTOS together with ASM? Forget about anything you know about PIC/AVR. It is completly another level.

reza05 said:

Is it reasonable to learn arm by assembly?

Click to expand...

If the purpose is to have the first contact with the architectures and their built-in peripherals by doing quite simple tasks, it is always valuable coding in assembly, but only that. There you can feel how the things works in the hardware level, although if you are already experienced with other simple cores you have already some perception on that. However, to make, let’s say, a professional code, there are a lot of reasons to avoid doing it in assembly language, as pointed above.

Thanks all,
I decided to start with IAR
but my problem is registers.
I have read some datasheet,but they are general,for example for cortex m3.
I want to know all stm32f103ret6 registers and other document just about this microcontroller
Could you please introduce me related datasheet

reza05 said:

but my problem is registers.
I have read some datasheet,but they are general,for example for cortex m3.

Click to expand...

Are you sayning you didn't find enough information about registers on datasheet of the specific part you intend to use ?

Exactly yes

Did you really read all their related documentation ( datasheet/ programming manual/ etc... ) ?
There you can find a lot of information covered in details.

The document you are asking for is the RM0008 Reference Manual and is quite easily to find when browsing STM32F103 documentation page.
https://www.st.com/content/ccc/reso...df/jcr:content/translations/en.CD00171190.pdf

I decided to start with IAR
but my problem is registers.

Click to expand...

If you are using IAR and ST, you can download all the examples for your MCU (or similar one). Go to menu Help -> Information Center -> Example Projects -> ST. There a message will be shown to download the content from ST. You will be suprised with how many examples are there in IAR. Practically you can operate almost all the MCU peripherals by copying code from those examples. ST's standard peripheral libray along with the examples, will help you a lot to get started.

I disagree that assembly language programming is not useful/important for ARM architecture.
If you are only writing higher level applications, then you obviously don't need it.
But, if you are writing code that must be highly reliable/fault recoverable and have to write exception handlers, not all the register-related stuff for decoding the fault type, prog conter, mode and exception decoding can be done readily done in C.
If you are going to be an embedded programmer, you really do need to dive into assembly from time to time.
Though, it is MUCH less often necessary than it used to be.