代码：

#include "iocc2530.h"

#define uchar unsigned char
#define uint unsigned int

#define D3 P1_0
#define D4 P1_1
#define D5 P1_3
#define D6 P1_4

#define SW1 P1_2
#define SW2 P0_1

#define LIGHT P1_7

void delay_ms(int x){
  for(int i=0;i<x;i++)
    for(int j=0;j<535;j++);
}

uint keyFlag =0;

void keyScan(){
  if(SW1==0){
    delay_ms(10);
    if(SW1==0){
      keyFlag++;
      if(keyFlag==5) keyFlag=4;
      while(SW1==0);
    }  
  }
  
  if(SW2==0){
    delay_ms(10);
    if(SW2==0){
      keyFlag=0;
      while(SW2==0);
    }  
  }
}


void main(){
  
  P1DIR |= 0X9B;   
  D3=D4=D5=D6=1;
  
  while(1){
    keyScan();
    switch(keyFlag){
      case 1: D4=1;
              D3=1;
              D6=0;
              D5=0;
              LIGHT = 0;
              break;
       case 2: D4=0;
              D3=1;
              D6=1;
              D5=0; 
              LIGHT = 0;
              break;
       case 3: D4=0;
              D3=0;
              D6=1;
              D5=1;
              LIGHT = 0;
              break;
        case 4: D4=1;
              D3=0;
              D6=0;
              D5=1; 
              LIGHT = 1;
              break;
       case 0: D4=1;
              D3=1;
              D6=1;
              D5=1;  
              LIGHT = 0;
              break;    
    } 
  }
}