EEPW论坛

#include <msp430x14x.h>

#define CPU_F ((double)8000000)
#define delay_us(x) __delay_cycles((long)(CPU_F*(double)x/1000000.0))
#define delay_ms(x) __delay_cycles((long)(CPU_F*(double)x/1000.0))

#define uchar unsigned char
#define uint  unsigned int
#define ulong unsigned long

void delayms(uint xms);
uchar key_checkin;

void main(void)
{
      WDTCTL=WDTPW+WDTHOLD; // Stop watchdog timer to prevent time out reset
      P2SEL=0x00;                   //P2普通IO功能
      P2DIR&=0x7f;        // 01111111
      P5SEL=0x00;                   //P2普通IO功能
      P5DIR=0xff;       // 11111111
      while(1)
      {
          key_checkin=P2IN;
          key_checkin&=0xf0;  
          if(key_checkin!=0xf0)
          {
              delayms(20);
              key_checkin=P2IN;
              key_checkin&=0xf0;
              if(key_checkin!=0xf0)
              { 
                 while(key_checkin!=0xf0);  //等待按键释放
                 P5OUT=0xff;
              }
          }
      }
}

void delayms(uint xms)
{
    uint i,j;
    for(i=xms;i>0;i--)
      for(j=110;j>0;j--);
}

请问这个程序有什么错误，为何下载到板子上没有反应呢？？？