本实验采用分时扫描的方式驱动8个发光二极管和4位数码管，共阴极接法，段驱动采用74HC245，位选驱动用NPN三极管。做本实验时需将拨码开关“SW2”和“SW5”的所有位拨到“ON”位置。实验现象是8个发光二极管轮流点亮，数码管显示“2010”。见下图：

程序流程图如下：

实验代码如下：

#include <hidef.h> /* for EnableInterrupts macro */
#include "derivative.h" /* include peripheral declarations */

#define LED_DAT PTBD
#define LED_CS0 PTCD_PTCD3
#define LED_CS1 PTCD_PTCD4
#define LED_CS2 PTCD_PTCD5
#define LED_CS3 PTCD_PTCD6
#define LED_CS4 PTCD_PTCD7
#define CS_ON   1
#define CS_OFF  0

typedef unsigned char uchar;

uchar tab[]={
        0x3F,/*0*/
        0x06,/*1*/
        0x5B,/*2*/
        0x4F,/*3*/
        0x66,/*4*/
        0x6D,/*5*/
        0x7D,/*6*/
        0x07,/*7*/
        0x7F,/*8*/
        0x6F/*9*/
};//0-9,-,全灭
//============================
//函数名:Init_io初始化I/O
//作用：初始化I/O
//输入参数：无
//返回参数：无
//=============================
void Init_io(void)
{ 
    //io初始值都为0
    PTBD = 0x00;
  PTCD_PTCD3=0;
  PTCD_PTCD4=0;
  PTCD_PTCD5=0;
  PTCD_PTCD6=0;
  PTCD_PTCD7=0;
    //io为输出
    PTBDD = 0xFF;
  PTCDD_PTCDD3=1;
  PTCDD_PTCDD4=1;
  PTCDD_PTCDD5=1;
  PTCDD_PTCDD6=1;
  PTCDD_PTCDD7=1;
    //高驱动强度
    PTBDS = 0xFF;
  PTCDS_PTCDS3=1;
  PTCDS_PTCDS4=1;
  PTCDS_PTCDS5=1;
  PTCDS_PTCDS6=1;
  PTCDS_PTCDS7=1;

}

//===================================================
//函数名：delay()
//作用：延时，该函数浪费CPU时间，在实际工程中酌情使用
//输入参数：无
//输出参数：无
//====================================================
void delay(void)
{
     word i;
     i=0x1ff;
     while(i--)__RESET_WATCHDOG();//喂狗;
}

void display(uchar d0 , uchar d1 , uchar d2 , uchar d3 , uchar d4) {
  //8个发光二极管
  LED_DAT = 0;
  LED_CS0 = CS_ON;
  LED_CS1 = CS_OFF;
  LED_CS2 = CS_OFF;
  LED_CS3 = CS_OFF;
  LED_CS4 = CS_OFF;
  LED_DAT = d0;
  delay();
  //第四个8
  LED_DAT = 0;
  LED_CS0 = CS_OFF;
  LED_CS1 = CS_OFF;
  LED_CS2 = CS_OFF;
  LED_CS3 = CS_OFF;
  LED_CS4 = CS_ON;
  LED_DAT = d1;
  delay();
  //第三个8
  LED_DAT = 0;
  LED_CS0 = CS_OFF;
  LED_CS1 = CS_OFF;
  LED_CS2 = CS_OFF;
  LED_CS3 = CS_ON;
  LED_CS4 = CS_OFF;
  LED_DAT = d2;
  delay();
  //第二个8
  LED_DAT = 0;
  LED_CS0 = CS_OFF;
  LED_CS1 = CS_OFF;
  LED_CS2 = CS_ON;
  LED_CS3 = CS_OFF;
  LED_CS4 = CS_OFF;
  LED_DAT = d3;
  delay();
  //第一个8
  LED_DAT = 0;
  LED_CS0 = CS_OFF;
  LED_CS1 = CS_ON;
  LED_CS2 = CS_OFF;
  LED_CS3 = CS_OFF;
  LED_CS4 = CS_OFF;
  LED_DAT = d4;
  delay(); 
}
void display_2010(void) {
  uchar cnt,i;
  for( cnt =1 ; cnt < 0x80 ; cnt <<= 1){
    for( i= 0 ; i<50 ; i++){
      display(cnt , tab[2] , tab[0] , tab[1] , tab[0]);
    }
  }
  for( i= 0 ; i<50 ; i++){
    display(cnt , tab[2] , tab[0] , tab[1] , tab[0]);
  }   
}
void main(void) {

  EnableInterrupts; /* enable interrupts */
  /* include your code here */
  Init_io();

  for(;;) {
    display_2010();
    //__RESET_WATCHDOG(); /* feeds the dog */
  } /* loop forever */
  /* please make sure that you never leave main */
}