/***************************************************************************/
/* DS1302.C                                                                */
/***************************************************************************/
#include	<stdio.h>
#include	<DS5000.h>		/* Register declarations for DS5000     */
sbit IO   = P0^2;
sbit SCLK = P0^1;
sbit RSTB = P0^0;
/***************************************************************************/
/* Prototypes                                                              */
/***************************************************************************/
void	clkwritebyte();
void	ramwritebyte();
uchar	rbyte_3w();
void	reset_3w();
void	wbyte_3w(uchar);
void	initialize_DS1302();
void	disp_clk_regs(uchar);
void	burstramrd();
void	burstramwr();
/* ----------------------------------------------------------------------- */
void reset_3w()
{
   SCLK = 0;
   RSTB = 0;
   RSTB = 1;
}
/* ----------------------------------------------------------------------- */
void wbyte_3w(uchar W_Byte)
{
uchar i;

	for(i = 0; i < 8; ++i)
	{
		IO = 0;
		if(W_Byte & 0x01)
		{
			IO = 1;	/* set port pin high to read data */
		}
		SCLK = 0;
		SCLK = 1;
		W_Byte >>= 1;
      }
}
/* ----------------------------------------------------------------------- */
uchar rbyte_3w()
{
uchar i;
uchar R_Byte;
uchar TmpByte;

	R_Byte = 0x00;
	IO = 1;
	for(i=0; i<8; ++i)
	{
		SCLK = 1;
		SCLK = 0;
		TmpByte = (uchar)IO;
		TmpByte <<= 7;
		R_Byte >>= 1;
		R_Byte |= TmpByte; 
	}
	return R_Byte;
}
/* ----------------------------------------------------------------------- */
void clkwritebyte()
{
uchar ClkAdd;
uchar ClkData;

	/* Get Clock Address & Data */
	printf("\nWrite Clock ADDRESS:");
	scanf("%bu", &ClkAdd);
	printf("\nWrite Clock DATA:");
	scanf("%bx", &ClkData);

	/* Prepare Command Byte for Clock Write */
	ClkAdd = ((ClkAdd * 2) | 0x80);

	reset_3w();
	wbyte_3w(ClkAdd);
	wbyte_3w(ClkData);
	reset_3w();
}
/* ----------------------------------------------------------------------- */
void ramwritebyte()
{
uchar ramadd;
uchar ramdata;

	/* Get Ram Address & Data */
	printf("\nWrite Ram ADDRESS (HEX):");
	scanf("%bx", &ramadd);
	printf("\nWrite Ram DATA (HEX):");
	scanf("%bx", &ramdata);

	/* Prepare Command Byte for Ram Write */
	ramadd = ((ramadd * 2) | 0xC0);

	reset_3w();
	wbyte_3w(ramadd);
	wbyte_3w(ramdata);
	reset_3w();
}
void disp_clk_regs(uchar loop)	/* ---- read and display clock registers ---- */
{
uchar lsec = 99, sec, min, hrs, dte, mon, day, yr;

do	/* Read & Display Clock Registers */
	{
		reset_3w();
		wbyte_3w(0xBF);	/* clock burst */
		sec = rbyte_3w();
		min = rbyte_3w();
		hrs = rbyte_3w();
		dte = rbyte_3w();
		mon = rbyte_3w();
		day = rbyte_3w();
		yr  = rbyte_3w();
		reset_3w();
		if(sec != lsec || !loop)	/* print once per second */
		{
			printf("\nYr   Day  Mon  Dte  Hrs  Min  Sec");
			printf("\n%2.bX   %2.bX   %2.bX   %2.bX", yr, day, mon, dte);
			printf("   %2.bX   %2.bX   %2.bX", hrs, min, sec);
			lsec = sec;
		}
		if(!loop)	break;
	}	while(!RI);
	if(loop)   _getkey();
}
void burstramrd()	/* ----------- read RAM in burst mode --------------- */
{
uchar rmary[31];
uchar i;

	reset_3w();
	wbyte_3w(0xFF);	/* RAM burst read */
	for (i=0; i<31; ++i)
	{
		rmary[i] = rbyte_3w();
	}
	reset_3w();

	printf("\nDS1302 Ram");

	printf("\n%2.bX %2.bX %2.bX %2.bX %2.bX %2.bX %2.bX %2.bX",
	rmary[0], rmary[1], rmary[2], rmary[3], rmary[4], rmary[5], rmary[6], rmary[7]);
	printf("\n%2.bX %2.bX %2.bX %2.bX %2.bX %2.bX %2.bX %2.bX",
	rmary[8], rmary[9], rmary[10], rmary[11], rmary[12], rmary[13], rmary[14], rmary[15]);
	printf("\n%2.bX %2.bX %2.bX %2.bX %2.bX %2.bX %2.bX %2.bX",
	rmary[16], rmary[17], rmary[18], rmary[19], rmary[20], rmary[21], rmary[22], rmary[23]);
	printf("\n%2.bX %2.bX %2.bX %2.bX %2.bX %2.bX %2.bX",
	rmary[24], rmary[25], rmary[26], rmary[27], rmary[28], rmary[29], rmary[30]);
}
void burstramwr()	/* ------ write one value to entire array --------- */
{
uchar ramdata;
uchar	i;

	/* Get Ram Data */
	printf("\nWrite Ram DATA (HEX):");
	scanf("%bx", &ramdata);

	reset_3w();
	wbyte_3w(0xfe);	/* RAM burst write */
	for (i=0; i<31; ++i)
	{
		wbyte_3w(ramdata);
	}
	reset_3w();
}
void initialize_DS1302()	/* ----------------------------------------- */
/* Note: NO error checking is done on the user entries! */
{
uchar	yr, mn, date, dy, hr, min, sec, day;

	printf("\nEnter the year (0-99): ");
	scanf("%bx", &yr);
	printf("\nEnter the month (1-12): ");
	scanf("%bx", &mn);
	printf("\nEnter the date (1-31): ");
	scanf("%bx", &date);
	printf("\nEnter the day (1-7): ");
	scanf("%bx", &dy);
	printf("\nEnter the hour (1-24): ");
	scanf("%bx", &hr);
	hr = hr & 0x3f;	/* force clock to 24 hour mode */
	printf("\nEnter the minute (0-59): ");
	scanf("%bx", &min);
	printf("\nEnter the second (0-59): ");
	scanf("%bx", &sec);

	reset_3w();
	wbyte_3w(0x8e);	/* control register */
	wbyte_3w(0);		/* disable write protect */
	reset_3w();
	wbyte_3w(0x90);	/* trickle charger register */
	wbyte_3w(0xab);	/* enable, 2 diodes, 8K resistor */
	reset_3w();
	wbyte_3w(0xbe);	/* clock burst write (eight registers) */
	wbyte_3w(sec);
	wbyte_3w(min);
	wbyte_3w(hr);
	wbyte_3w(date);
	wbyte_3w(mn);
	wbyte_3w(dy);
	wbyte_3w(yr);
	wbyte_3w(0);		/* must write control register in burst mode */
	reset_3w();
}
main (void)		/* ----------------------------------------------------- */
{
uchar i, M, M1;

	while (1)
	{ 
	printf("\nDS1302\n");
	printf("I. initialize DS1302\n");
	printf("CW. Write Byte  CR. Read Time\n");
	printf("RW. Write RAM   RR. Read RAM\n");
	printf("\nEnter Menu Selection:");

	M = _getkey();

	switch(M) 
	{
		case 'C':
		case 'c':
		printf("\rEnter Clock Routine to run:C");
		M1 = _getkey();

		switch(M1) 
            {
			case 'R':
			case 'r':	disp_clk_regs(1);	break;

	            case 'W':
      	      case 'w':	clkwritebyte();	break;
		}
		break;

		case 'I':
		case 'i':	initialize_DS1302();	break;

		case 'R':
		case 'r':
		printf("\rEnter Ram Routine to run:R");
		M1 = _getkey();

		switch(M1) 
		{
		case 'B':
		case 'b':	ramwritebyte();	break;
		case 'R':
		case 'r':	burstramrd();	break;
		case 'W':
		case 'w':	burstramwr();	break;
		}
		break;
	}
   }
}