数码管倒计时60秒

#include

#define LEDLen 2
#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;
unsigned char Pos;
unsigned char LED;

Pos = 0x01; // 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 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 == 0)
{
Second = 60;
}
}
}

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

IE = 0x82; // EA=1, IT0 = 1
Second = 60;
C100us = Tick;
TR0 = 1; // 启动定时器0

while (1)
{
LEDBuf[0] = LEDMAP[Second%10] | 0x80;
LEDBuf[1] = LEDMAP[Second/10];
DisplayLED();
}
}