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how to use global pointer of C in assembly program

New Chinese bird 

/*******************************************/
/*compiler Keil C51 v6.23*/
/*name：main*/
unsigned char xdata temp;
unsigned char xdata *p;
void func(void);
void main(void)
{	
	unsigned char xdata i;
 	while(1)
	{
		p = &temp;	
		*p = 98;	
		func();
		i = *p;
	}
}
/******************************************/
/*--------------------------------------
compile following program to assembly program, then link with the main function.ERROR!!! Why and how to chang the assembly program.please help me,thank you.!
------------------------------------------*/
#pragma src(MYPTR.A51) small

extern unsigned char xdata *p;

void func(void)
{	
	*p = 0xdd;
}
my E-mail:inspra@xjgroup.com
name:huangjian

Parents
  • 0 in reply to New Chinese bird

    It appears that your C program which you use SRC with is ALWAYS compiled in SMALL memory model. The following line:

    #pragma src(MYPTR.A51) small

    tells the compiler to compile in the small memory model.

    If you compile other parts of your program in LARGE or COMPACT memory model, the memory areas used for variables won't match.

    Jon

Reply
  • 0 in reply to New Chinese bird

    It appears that your C program which you use SRC with is ALWAYS compiled in SMALL memory model. The following line:

    #pragma src(MYPTR.A51) small

    tells the compiler to compile in the small memory model.

    If you compile other parts of your program in LARGE or COMPACT memory model, the memory areas used for variables won't match.

    Jon

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