初学者程序有点问题想指教下

xiazeyang1008 · 发表于 2011-11-5 22:18:07

#include<stm32f10x_lib.h>
#include"sys.h"
#include"usart.h"
#include"delay.h"

#define LED0 PFout(6)
#define LED1 PFout(7)
#define LED2 PFout(9)
#define LED3 PFout(10)
void LED_Init(void)
{
RCC->APB2ENR|=1<<7;
GPIOF->CRH&=0XFFFFFF0F;
GPIOF->CRH|=0X00000030;
GPIOF->ODR|=1<<9;
GPIOF->CRH&=0XFFFFF0FF;
GPIOF->CRH|=0X00000300;
GPIOF->ODR|=1<<10;
GPIOF->CRL&=0XF0FFFFFF;
GPIOF->CRL|=0X03000000;
GPIOF->ODR|=1<<6;
GPIOF->CRL&=0X0FFFFFFF;
GPIOF->CRL|=0X30000000;
GPIOF->ODR|=1<<7;

}

u8 KEY_Scan(void)
{ if(NRST==0)
    { delay_ms(10);
   if (NRST==0 )
       { return 1;}
else
      return 0;
}
   else
    return 0;
}

int main()
{ Stm32_Clock_Init(9);
delay_init(72);
LED_Init();
LED0=0;
LED1=0;
LED2=1;
LED3=1;
while(1)
{ u8 t;
t=KEY_Scan();
if(t==1)
{LED0=!LED0;
LED1=!LED1;
LED2=!LED2;
LED3=!LED3;
}
else
{LED0=LED0;
   LED1=LED1;
   LED2=LED2;
   LED3=LED3;
}
}
}
问题：要通过复位键（接在NRST上，有上拉电阻）控制LED，怎么把NRST定义成输入啊，我直接读NRST,编译显示NREST未定义，我是初学者，指教下，帮忙写下这个定义这个按键的代码