h18.c

51单片机程序C和汇编

#include <reg51.h>

#define LEDLen 6
#define PB1    2  // 164 时钟位
#define PB0    1  // 164 数据位

xdata unsigned char OUTBIT _at_ 0x8002;   // 位控制口
xdata unsigned char OUTSEG _at_ 0x8004;   // 段控制口

unsigned char LEDBuf[LEDLen];  // 显示缓冲
code unsigned char LEDMAP[] = {  // 八段管显示码
  0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07,
  0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71
};

void Delay(unsigned char CNT)
{
  unsigned char i;

  while (CNT-- !=0)
    for (i=100; i !=0; i--);
}

void DisplayLED()
{
  unsigned char i, j;
  unsigned char Pos;
  unsigned char LED;

  Pos = 0x20;  // 从左边开始显示
  for (i = 0; i < LEDLen; i++) {
    OUTBIT = 0;     // 关所有八段管
    LED = LEDBuf[i];
    OUTSEG = LED;
    OUTBIT = Pos;  // 显示一位八段管
    Delay(1);
    Pos >>= 1;     // 显示下一位
  }
}

// ===============================================================================

#define Tick   10000     // 10000 x 100us = 1s
#define T100us (256-50)  // 100us时间常数(6M)

unsigned char Hour, Minute, Second;
unsigned int C100us;     // 100us记数单元

void T0Int() interrupt 1
{
  C100us--;
  if (C100us == 0) {
    C100us = Tick;     // 100us 记数器为0, 重置记数器
    Second++;
    if (Second == 60) {
      Second = 0;
      Minute++;
      if (Minute == 60) {
        Minute = 0;
        Hour++;
        if (Hour == 24) Hour = 0;
      }
    }
  }
}

void main()
{
  TMOD = 0x02;   // 方式2, 定时器
  TH0  = T100us;
  TL0  = T100us;

  IE   = 0x82;   // EA=1, IT0 = 1

  Hour   = 0;
  Minute = 0;
  Second = 0;
  C100us = Tick;
  TR0    = 1;    // 启动定时器0

  while (1) {
    LEDBuf[0] = LEDMAP[Hour/10];
    LEDBuf[1] = LEDMAP[Hour%10] | 0x80;
    LEDBuf[2] = LEDMAP[Minute/10];
    LEDBuf[3] = LEDMAP[Minute%10] | 0x80;
    LEDBuf[4] = LEDMAP[Second/10];
    LEDBuf[5] = LEDMAP[Second%10];

    DisplayLED();
  }
}