时钟芯片DS1302程序

DS1302是DALLAS公司推出的涓流充电时钟芯片，内含有一个实时时钟/日历和31字节静态RAM，通过简单的串行接口与单片机进行通信实时时钟/日历电路。提供秒分时日星期月年的信息，每月的天数和闰年的天数可自动调整，时钟操作可通过AM/PM指示决定采用24或12小时格式。DS1302与单片机之间能简单地采用同步串行的方式进行通信，仅需用到三个口线：1）RST 复位，2）SDA 数据线，3）SCK 串行时钟。时钟/RAM的读/写数据以一个字节或多达31个字节的字符组方式通信。以下程序包含DS1302的主要操作以及数据存取功能。

Ds1302.h代码

#define	DS1302_VT_SECOND	0
#define	DS1302_VT_MINURE	1
#define	DS1302_VT_HOUR		2
#define	DS1302_VT_DATE		3
#define	DS1302_VT_MONTH		4
#define	DS1302_VT_DAY		5
#define	DS1302_VT_YEAR		6

extern unsigned char Ds1302_Buff[7]; //秒分时日月周年2011-07-14 12:00:00

void Ds1302_Init();
void Ds1302_Read_RTC(void);
void Ds1302_Set_RTC(void);
unsigned char Ds1302_Read_Value(unsigned char valueType);
void Ds1302_Set_Value(unsigned char valueType, unsigned char value);

Ds1302.c代码

#include "intrins.h"
#include "Hardware.h"
#include "Ds1302.h"

sbit SCK = P1^3;	//时钟	
sbit SDA = P1^4;	//数据	
sbit RST = P1^5;    // DS1302复位

unsigned char Ds1302_Buff[7]; //秒分时日月周年
code unsigned char write_rtc_address[7]={0x80,0x82,0x84,0x86,0x88,0x8a,0x8c}; //秒分时日月周年 最低位读写位
code unsigned char read_rtc_address[7]={0x81,0x83,0x85,0x87,0x89,0x8b,0x8d};  

void Ds1302_Delay() 	
{
	unsigned char t_delay = 100;
	while(t_delay--);
}

void Ds1302_Write_Byte(unsigned char temp) 
{
	unsigned char i;
	for (i=0; i<8; i++) //循环8次 写入数据
	{ 
		SCK = 0;
		SDA = temp & 0x01; //每次传输低字节 
		temp >>= 1; //右移一位
		SCK = 1;
	}
}

unsigned char Ds1302_Read_Byte()
{
	unsigned char i, temp = 0x00;
	for (i=0; i<8; i++) //循环8次 读取数据
	{		
		temp >>= 1; //右移一位
		SCK = 0;
		_nop_();
		if(SDA)
			temp |= 0x80; //每次传输低字节		
		SCK = 1;
	} 
	return temp;
}

void Ds1302_Prepare_IO()
{
	RST = 0;
	Ds1302_Delay();
	SCK = 0;
	_nop_();
	RST = 1;	
	Ds1302_Delay();
}

void Ds1302_Write(unsigned char address, unsigned char dat)     
{
	Ds1302_Prepare_IO();
	Ds1302_Write_Byte(address);	//发送地址
	Ds1302_Write_Byte(dat); //发送数据
	RST = 0; //恢复
}

unsigned char Ds1302_Read(unsigned char address)
{
	unsigned char temp;

	Ds1302_Prepare_IO();
	Ds1302_Write_Byte(address);
	temp = Ds1302_Read_Byte();
	RST = 0;
	return temp;
}

void Ds1302_Read_RTC(void)	//读取 日历
{
	unsigned char i, *p;
	p = read_rtc_address; //地址传递
	for(i=0; i<7; i++) //分7次读取 秒分时日月周年
	{
		Ds1302_Buff[i] = Ds1302_Read(*p);
		p++;
	}
}

void Ds1302_Set_RTC(void) //设定 日历
{
	unsigned char i, *p;
	
	Ds1302_Write(0x8E, 0X00);
	p = write_rtc_address; //传地址	
 	for(i=0; i<7; i++) //7次写入 秒分时日月周年
 	{
		  Ds1302_Write(*p, Ds1302_Buff[i]);
 		  p++;  
	}
	Ds1302_Write(0x8E, 0x80);
}

void Ds1302_Init()
{
   Ds1302_Write(0x8e, 0x00); //写保护控制字，允许写
   Ds1302_Write(0x80, 0x00); //开启时钟
   Ds1302_Write(0x90, 0x5c); //禁止充电
}

unsigned char Ds1302_Read_Value(unsigned char valueType)
{
	unsigned char temp = Ds1302_Buff[valueType];
	unsigned char hour12;

	if (valueType == 2)
	{
		if (temp & 0x80)
		{
			// 12小时转24小时
			hour12 = ((temp & 0x10) >> 4) * 10 + (temp & 0x0F);

			if (temp & 0x20)
				return (hour12 + 12) % 24;
			else
				return hour12;

} else return ((temp & 0x30) >> 4) * 10 + (temp & 0x0F); } else return (temp >> 4) * 10 + (temp & 0x0F); } void Ds1302_Set_Value(unsigned char valueType, unsigned char value) { unsigned char highBits = value / 10; highBits <<= 4; if (valueType == 2) { Ds1302_Buff[2] = highBits + value % 10; } else Ds1302_Buff[valueType] = highBits + value % 10; }