Hi,

in a thumb-assembly file (my toolchain is gcc 4.8), I want to replace a branch with address assignment to the program-counter.
So instead of:

b   lbl

I want to have something like:

pc = address(lbl)

This solution works. Here, I use the following code to…

i want to a very easy way of setting this bit

I'm new of arm processor and I'd like to import a variable in a .s file the variable is definited in a c file:

#define INIT_VAR 1

.......

extern uint32_t save_mem = INIT_VAR;

or better I need to write inside a memory address of that variable.

Background

 I'm working part-time on a Cortex M0+ based SoC converting a very processor-intensive section of C++ code (inner-loop executed 10s of 1000s of times a second & compiles to over 400 instructions using GNU O3) and after almost 3 months of work…

I want to store the value of Program Counter(pc) to a memory location.

I did this, 

    LDR R1, =[0x20000000]

    STR R15, [R1,#0]

I got an error saying, "Error: r15(pc) not allowed here -- `str R15,[R1,#0]'.

How should I get over this error?

Cannot configure interupts of TIM6 on stm32f103 board

Does my NVIC configuration wrong?

Code:

@ stm32f103 timer & interrupt test by laper_s (from 2019-02-02)

.thumb
.cpu cortex-m3
.syntax unified

.word   0x20005000
.word   start + 1

b   start…