单片机换晶振后Ds1302时间走快的问题? -

#include <STC12C5A60S2.H>
#include "intrins.h"
sbit DS1302_CE = P0^0;
sbit DS1302_CK = P0^1;
sbit DS1302_IO = P0^2;
bit flag200ms = 0; //200ms定时标志
unsigned char T0RH = 0; //T0重载值的高字节
unsigned char T0RL = 0; //T0重载值的低字节
void ConfigTimer0(unsigned int ms);
void InitDS1302();
unsigned char DS1302SingleRead(unsigned char reg);
extern void InitLcd1602();
extern void LcdShowStr(unsigned char x, unsigned char y, unsigned char *str);
void main()
{
unsigned char i;
unsigned char psec=0xAA; //秒备份，初值AA确保首次读取时间后会刷新显示
unsigned char time[8]; //当前时间数组
unsigned char str[12]; //字符串转换缓冲区
EA = 1; //开总中断
ConfigTimer0(1); //T0定时1ms
InitDS1302(); //初始化实时时钟
InitLcd1602(); //初始化液晶
while (1)
{
if (flag200ms) //每200ms读取依次时间
{
flag200ms = 0;
for (i=0; i<7; i++) //读取DS1302当前时间
{
time[i] = DS1302SingleRead(i);
}
if (psec != time[0]) //检测到时间有变化时刷新显示
{
str[0] = '2'; //添加年份的高2位：20
str[1] = '0';
str[2] = (time[6] >> 4) + '0'; //“年”高位数字转换为ASCII码
str[3] = (time[6]&0x0F) + '0'; //“年”低位数字转换为ASCII码
str[4] = '-'; //添加日期分隔符
str[5] = (time[4] >> 4) + '0'; //“月”
str[6] = (time[4]&0x0F) + '0';
str[7] = '-';
str[8] = (time[3] >> 4) + '0'; //“日”
str[9] = (time[3]&0x0F) + '0';
str[10] = '\0';
LcdShowStr(0, 0, str); //显示到液晶的第一行
str[0] = (time[5]&0x0F) + '0'; //“星期”
str[1] = '\0';
LcdShowStr(11, 0, "week");
LcdShowStr(15, 0, str); //显示到液晶的第一行
str[0] = (time[2] >> 4) + '0'; //“时”
str[1] = (time[2]&0x0F) + '0';
str[2] = ':'; //添加时间分隔符
str[3] = (time[1] >> 4) + '0'; //“分”
str[4] = (time[1]&0x0F) + '0';
str[5] = ':';
str[6] = (time[0] >> 4) + '0'; //“秒”
str[7] = (time[0]&0x0F) + '0';
str[8] = '\0';
LcdShowStr(4, 1, str); //显示到液晶的第二行
psec = time[0]; //用当前值更新上次秒数
}
}
}
}
void BusDelay()
{
_nop_();
_nop_();
_nop_();
_nop_();
}
/* 发送一个字节到DS1302通信总线上 */
void DS1302ByteWrite(unsigned char dat)
{
unsigned char mask;
for (mask=0x01; mask!=0; mask<<=1) //低位在前，逐位移出
{
if ((mask&dat) != 0) //首先输出该位数据
DS1302_IO = 1;
else
DS1302_IO = 0;
DS1302_CK = 1; //然后拉高时钟
BusDelay();
DS1302_CK = 0; //再拉低时钟，完成一个位的操作
}
DS1302_IO = 1; //最后确保释放IO引脚
}
/* 由DS1302通信总线上读取一个字节 */
unsigned char DS1302ByteRead()
{
unsigned char mask;
unsigned char dat = 0;
for (mask=0x01; mask!=0; mask<<=1) //低位在前，逐位读取
{
if (DS1302_IO != 0) //首先读取此时的IO引脚，并设置dat中的对应位
{
dat |= mask;
}
DS1302_CK = 1; //然后拉高时
BusDelay();
DS1302_CK = 0; //再拉低时钟，完成一个位的操作
}
return dat; //最后返回读到的字节数据
}
/* 用单次写操作向某一寄存器写入一个字节，reg-寄存器地址，dat-待写入字节 */
void DS1302SingleWrite(unsigned char reg, unsigned char dat)
{
DS1302_CE = 1; //使能片选信号
DS1302ByteWrite((reg<<1)|0x80); //发送写寄存器指令
DS1302ByteWrite(dat); //写入字节数据
DS1302_CE = 0; //除能片选信号
}
/* 用单次读操作从某一寄存器读取一个字节，reg-寄存器地址，返回值-读到的字节 */
unsigned char DS1302SingleRead(unsigned char reg)
{
unsigned char dat;
DS1302_CE = 1; //使能片选信号
DS1302ByteWrite((reg<<1)|0x81); //发送读寄存器指令
dat = DS1302ByteRead(); //读取字节数据
DS1302_CE = 0; //除能片选信号
return dat;
}
/* DS1302初始化，如发生掉电则重新设置初始时间 */
void InitDS1302()
{
unsigned char i;
unsigned char code InitTime[] = {
0x70,0x30,0x07, 0x30, 0x05, 0x06, 0x21
};
DS1302_CE = 0; //初始化DS1302通信引脚
DS1302_CK = 0;
i = DS1302SingleRead(0); //读取秒寄存器
if ((i & 0x80) != 0) //由秒寄存器最高位CH的值判断DS1302是否已停止
{
DS1302SingleWrite(7, 0x00); //撤销写保护以允许写入数据
for (i=0; i<7; i++) //设置DS1302为默认的初始时间
{
DS1302SingleWrite(i, InitTime[i]);
}
}
}
/* 配置并启动T0，ms-T0定时时间 */
void ConfigTimer0(unsigned int ms)
{
unsigned long tmp; //临时变量
AUXR=0x80; //不分频
tmp = 33177600; //定时器计数频率
tmp = (tmp * ms) / 1000; //计算所需的计数值
tmp = 65536 - tmp; //计算定时器重载值
tmp = tmp + 28; //补偿中断响应延时造成的误差
T0RH = (unsigned char)(tmp>>8); //定时器重载值拆分为高低字节
T0RL = (unsigned char)tmp;
TMOD &= 0xF0; //清零T0的控制位
TMOD |= 0x01; //配置T0为模式1
TH0 = T0RH; //加载T0重载值
TL0 = T0RL;
ET0 = 1; //使能T0中断
TR0 = 1; //启动T0
}
/* T0中断服务函数，执行200ms定时 */
void InterruptTimer0() interrupt 1
{
static unsigned int tmr200ms = 0;
TH0 = T0RH; //重新加载重载值
TL0 = T0RL;
tmr200ms++;
if (tmr200ms >= 200) //定时200ms
{
tmr200ms = 0;
flag200ms = 1;
}
}

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