topic Re: How to cause function having only its address??? in S12 / MagniV Microcontrollers

How to cause function having only its address???

admin — Fri, 05 Dec 2008 15:26:59 GMT

Greetings, prompt as it is possible to solve a following problem: it is necessary to cause function, but there is only its address. I write in C++ on CW4.7 for S12XDP. Thought it will be possible to use Assembler inserts, but at me nothing has left.

Re: How to cause function having only its address???

CrasyCat — Fri, 05 Dec 2008 19:00:27 GMT

Hello

Not sure I understand the question here.

Are you looking for a way to call a function which reside at a specified address from a ANSI C function?

If this is what you are looking for you can use a constant function pointer to call the function.

Something as follows:
void (*const fktPtr)(void) = (void(*)(void))0x1234;

   void main(void) {
     fktPtr();
   }

This will call function located at address 0x1234.

CrasyCat

Re: How to cause function having only its address???

admin — Thu, 11 Dec 2008 14:19:14 GMT

Thanks for the help, I also had it in view of. I believed that for nonstatic function such design will not work. Thanks :smileywink:

Re: How to cause function having only its address???

Lundin — Thu, 11 Dec 2008 22:28:35 GMT

C++ will not allow you to convert the address of a non-static member function of a class to a function pointer. For such cases you have to use non-standard extensions to the language, such as inline assembler.

This is one of the reasons why C++ is less suitable than C for embedded systems.

Re: How to cause function having only its address???

admin — Thu, 11 Dec 2008 23:17:34 GMT

Hello Lundin.

Lundin wrote: C++ will not allow you to convert the address of a non-static member function of a class to a function pointer. For such cases you have to use non-standard extensions to the language, such as inline assembler.

Completely with you it agree, I on tried to use the assembler, but at me that it has not turned out...... Has not refused if somebody has helped me in the decision of the given problem....