12c887.c

全国电子设计大赛:智能电动车的设计.实现功能:以AT89C52单片机为核心

//*************************************************************************************************
//  Module Name :  12C887.C
//  CreateDate  :  2005-01-09
//  ModifData   :  2005-05-05
//  Description :  
//  Author      :  李远正
//  Version     :  V1.0
//*************************************************************************************************

#include <absacc.h>
#include "12C887.H"

//-------------------------------------------------------------------------------------------------
//-------------------------------------------------------------------------------------------------
// 设置系统时间
void Setup12C887( unsigned char *p ) 
{
	unsigned char i;

	for ( i=0; i<20; i++ ) { temp = RTC_REGA; if ( (temp&0x80) == 0 ) break; } // Wait for ... 

	RTC_REGA	= 0x70; 
	RTC_REGB	= 0xa2; 
	RTC_SEC		= *p++; 
	RTC_SEC_ALM	= 0xff; 
	RTC_MIN 	= *p++;
	RTC_MIN_ALM	= 0xff; 
	RTC_HOU		= *p++; 
	RTC_HOU_ALM	= 0xff; 
	RTC_DAY_WEK	= *p++; 
	RTC_DAY_MON	= *p++;
	RTC_MON		= *p++; 
	RTC_YEAR	= *p++; 
	RTC_REGB	= 0x26; 
	RTC_REGA	= 0x20;
}

//-------------------------------------------------------------------------------------------------
// 读取系统时间
void Read12C887( unsigned char *p ) 
{
	unsigned char i;

	for ( i=0; i<20; i++ ) { temp = RTC_REGA; if ( (temp&0x80) == 0 ) break; } // Wait for ... 

	*p++ = RTC_SEC; 
	*p++ = RTC_MIN; 
	*p++ = RTC_HOU; 
	*p++ = RTC_DAY_WEK;
	*p++ = RTC_DAY_MON; 
	*p++ = RTC_MON; 
	*p++ = RTC_YEAR;
}		

//-------------------------------------------------------------------------------------------------
// 启动时钟
void Start12C887( void ) 	
{
	RTC_REGA    = 0x70; 	// 开启晶体振荡器
	RTC_REGB    = 0xa2; 	// 禁止芯片更新，允许闹钟中断，二进制输出，设置为24小时制 
	RTC_SEC_ALM = 0xff; 	// 清闹钟
	RTC_MIN_ALM = 0xff; 
	RTC_HOU_ALM = 0xff;
	RTC_REGB    = 0x26; 	// 允许更新
	RTC_REGA    = 0x20;		// 晶体振荡器开启并保持时钟运行
}

//=================================================================================================
// 将一个字节写入12c887的RAM
void Write12C887RAM( unsigned int address,unsigned char datum )
{
	unsigned char xdata *p;
	unsigned char i;

	for ( i=0; i<20; i++ ) { temp = RTC_REGA; if ( (temp&0x80) == 0 ) break; } // Wait for ... 

	p  = (unsigned char xdata *)address;
	*p = datum;
}

//-------------------------------------------------------------------------------------------------
// 从RAM中读出一个字节
unsigned char Read12C887RAM( unsigned int address )
{
	unsigned char xdata *p;	
	unsigned char i;
	
	for ( i=0; i<20; i++ ) { temp = RTC_REGA; if ( (temp&0x80) == 0 ) break; } // Wait for ... 

	p    = (unsigned char xdata *)address;
	temp = *p;

	return ( temp );
}

//=================================================================================================
// Select one of the 13 taps on the 15–stage divider
// or disable the divider output.
// Generate an output square wave (SQW)
void SetSQW( unsigned char frequency )
{
	temp     = RTC_REGA;
	temp    &= 0xF0;
	temp    |= frequency;
	RTC_REGA = temp;
}