ds1302.c

Digital Clock Source using ATmega8515 and 7Segment

#include "ds1302.h"
#include "global.h"
#include "delay.h"

void Init_DS1302(void)
{
	sbi(DS1302_DDR, DS1302_CLK);
	sbi(DS1302_DDR, DS1302_CE);
	sbi(DS1302_DDR, DS1302_IO);

	cbi(DS1302_PORT, DS1302_CLK);
	cbi(DS1302_PORT, DS1302_CE);
	cbi(DS1302_PORT, DS1302_IO);

  	DS1302_Write(DS1302_WP, 0x00);                         	// write protect off
  	DS1302_Write(DS1302_SET, 0xA5);                          	// charge,diode,resistor
  	DS1302_Write(DS1302_HOUR, DS1302_Read(DS1302_HOUR) & 0x7f);    	// 24hour set
  	DS1302_Write(DS1302_SECOND, DS1302_Read(DS1302_SECOND)&0x7f); 	// ch clear

}

unsigned char DS1302_Read(unsigned char addr)
{
	unsigned char dval;
 	unsigned char count;

  	dval = addr|0x01;        		// Read 疙飞 傈价矫 付瘤阜 厚飘绰 1肺 Set登绢具 茄促.
  	sbi(DS1302_DDR,DS1302_IO);      // io= input ddr set
	sbi(DS1302_PORT,DS1302_CE);     // ce= low
	cbi(DS1302_PORT,DS1302_IO);     // io= input ddr set

  	delay_us(5);

  	for(count=0;count<8;count++)
	{   		
		// 窍困官捞飘何磐 傈价
		if(dval&0x01)
    		sbi(DS1302_PORT,DS1302_IO);   // io= high
   		else
    		cbi(DS1302_PORT,DS1302_IO);   // io= low   

   		dval>>=1;
   		cbi(DS1302_PORT,DS1302_CLK);    // ck= low
   		NOP;
		NOP;
   		sbi(DS1302_PORT,DS1302_CLK);    // ck= high
  	}

  	cbi(DS1302_DDR,DS1302_IO);      // io= input
	sbi(DS1302_PORT,DS1302_IO);      // io= input
  	dval=0x00;

  	for(count=0;count<8;count++)
  	{
  		if(bit_is_set(DS1302_PIN,DS1302_IO))
    		dval |= 0x80;

   		dval>>=1;
   		sbi(DS1302_PORT,DS1302_CLK);    // ck= high
   		NOP;
		NOP;
   		cbi(DS1302_PORT,DS1302_CLK);    // ck= low
  	}

  	cbi(DS1302_PORT,DS1302_CE);     // ce= low
  	NOP;
  	sbi(DS1302_DDR,DS1302_IO);      // io= output ddr set
  	return dval;
}
 

void DS1302_Write(unsigned char addr, unsigned char data)
{
	unsigned char count;
	sbi(DS1302_DDR,DS1302_IO);   
  	sbi(DS1302_PORT,DS1302_CE);	
  	delay_us(5);

  	for(count=0;count<8;count++)
	{
   		if(addr&0x01)
    		sbi(DS1302_PORT,DS1302_IO);
   		else
    		cbi(DS1302_PORT,DS1302_IO);

   		addr >>= 1;
   		sbi(DS1302_PORT,DS1302_CLK);
   		NOP;
		NOP;
   		cbi(DS1302_PORT,DS1302_CLK);
  	}
  	
	for(count=0;count<8;count++)
	{
   		if(data&0x01)
    		sbi(DS1302_PORT,DS1302_IO);
   		else
    		cbi(DS1302_PORT,DS1302_IO);   

   		data>>=1;
   		sbi(DS1302_PORT,DS1302_CLK);
   		NOP;
		NOP;
   		cbi(DS1302_PORT,DS1302_CLK);
  	}
  	cbi(DS1302_PORT,DS1302_CE);
  	NOP;
	NOP;
  	cbi(DS1302_PORT,DS1302_IO);
}