/C与汇编相互调用/

时间：2009-06-22 来源：creatory

/*C与汇编相互调用*/ /*C文件*/
/*function:flash led.c*/
#define GPFCON (*(volatile unsigned long *)0x56000050)
#define GPFDAT (*(volatile unsigned long *)0x56000054)
#define GPFUP (*(volatile unsigned long *)0x56000058)
/*declare asm function*/
extern int delay(int t); int main(void){
/*先清零再置1*/
/*0101,0101,xxxx,xxxx*/
GPFCON=(GPFCON&0x00FF)|0x5500;
GPFUP|=0xFF00; //dislable pull up
while(1){
  /*GPF4 ouput 0:1110,0000*/
  GPFDAT=(GPFDAT &0x0F)|0xE0;
  delay(0x5FFFFF);
  /*GPF5 output 0:1101,0000*/
  GPFDAT=(GPFDAT &0x0F)|0xD0;
  delay(0x5FFFFF);
  /*GPF6 output 0:1011,0000*/
  GPFDAT=(GPFDAT&0x0F)|0xB0;
  delay(0x5FFFFF);
  /*GPF7 output 0:0111,0000*/
  GPFDAT=(GPFDAT &0x0F)|0x70;
  delay(0x5FFFFF);

}
return 0;
} /*汇编文件*/ EXPORT delay
AREA DELAY,CODE,READONLY
delay
SUB R0,R0,#0x1
CMP R0,#0x0
BNE delay
MOV PC,LR

END

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