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#include "8051.h" 
#include "serial.h" 

#define SCLK P2_0 
#define DATA_IO P2_1 
#define RESET_ P2_2 
#define YELLOW_LED P3_6 
#define RED_LED P3_7 

unsigned char serial_storage=0x00; 
unsigned char display; 

void usec_wait(unsigned char); 
void msec_wait(unsigned char); 
void sec_wait(unsigned char); 
void convert_and_send(unsigned char); 
unsigned char receive_convert(void); 


//************************************************************** 
//DELAY FUNCTIONS - USEC_WAIT ; MSEC_WAIT ; SEC_WAIT 
//************************************************************** 
void usec_wait(unsigned char k) 
{ 
while(k!=0) 
{ 
k--; 
} 
} 
////////////////////////////////////////////////////// 
void msec_wait(unsigned char j) 
{ 
while(j!=0) 
{ 
usec_wait(165); 
j--; 
} 
} 
////////////////////////////////////////////////////// 
void sec_wait(unsigned char sec_count) 
{ 
while(sec_count!=0) 
{ 
msec_wait(250); 
msec_wait(250); 
msec_wait(250); 
msec_wait(250); 
sec_count--; 
} 
} 
////////////////////////////////////////////////////// 

//************************************************************** 
//SERIAL INTERRUPT FUNCTION 
//************************************************************** 

void serial_interrupt() interrupt 4 
{ 
if(TI) 
TI=0; 

if(RI) 
{ 
serial_storage=SBUF; 
usec_wait(1); 
RI=0; 
RED_LED=1; 
} 
} 


//******************************************************************* 
//FUNCTION THAT SENDS ADDRESS OR DATA_IO AFTER CONVERTING IT TO BITS 
//******************************************************************* 
void convert_and_send(unsigned char hex_data1) 
{ 
bit sending_bit; 
unsigned char comparing_byte=0x01; 
unsigned char i; 
unsigned char storing_byte=0x00; 
SBUF=hex_data1; 
usec_wait(5); 

for(i=0;i<8;i++) 
{ 
storing_byte=(hex_data1&comparing_byte); 
if(storing_byte==0x00) 
sending_bit=0; 
else 
sending_bit=1; 
SCLK=0; 
SCLK=0; 
DATA_IO = sending_bit; //Clock to DATA_IO delay is 250ns (max) 
comparing_byte<<=1; 
SCLK=1; 
} 
serial_storage=0x00; 
usec_wait(2); 
} 


//************************************************************************************** 
//FUNCTION THAT RECEIVES DATA AND THEN CONVERTS IT TO CHARACTER AND PASSES TO ITS CALLER 
//************************************************************************************** 
unsigned char receive_convert(void) 
{ 

bit receiving_bit; 
unsigned char comparing_byte=0x00; 
unsigned char i=0; 
unsigned char received_data=0x00; 

for(i=0;i<8;i++) 
{ 
SCLK=1; 
SCLK=1; //For giving a DEALY 
SCLK=0; 
receiving_bit=DATA_IO; 
if(receiving_bit==0) 
comparing_byte=0x00; 
else 
comparing_byte=0x80; //comparing byte is 10000000 as the bit is to be placesd in the MSB position 
received_data=received_data>>1; 
received_data=received_data|comparing_byte; 
} 
return(received_data); 
} 


void main() 
{ 

initialize_serial(); //INITIALIZES THE SERIAL PORT 

//FUNCTION THAT INITIALIZES THE TIMMER IC BY SETTING CH AND WP BIT 
RED_LED=0; //BOTH LED's GLOW WHEN THE RTC IS BEING SET 
YELLOW_LED=0; 
RESET_=1; 
msec_wait(1); 
convert_and_send(0x8E); //SETS THE WP BIT AS ZERO 
msec_wait(1); 
convert_and_send(0x00); 
RESET_=0; 
msec_wait(1); 
RESET_=1; 
msec_wait(1); 
convert_and_send(0x80); //SETS THE CH BIT AS ZERO 
msec_wait(1); 
convert_and_send(0x00); 
RESET_=0; 
msec_wait(1); 

sec_wait(4); 

RESET_=1; //INITIALIZING the HT1380 
msec_wait(1); 
convert_and_send(0xBE); //Burst Mode Command 
msec_wait(1); 
convert_and_send(0x00); //Sec register, Including the CH=0 
msec_wait(1); 
convert_and_send(0x00); //min 
msec_wait(1); 
convert_and_send(0x10); //hour 
msec_wait(1); 
convert_and_send(0x10); //date 
msec_wait(1); 
convert_and_send(0x05); //month 
msec_wait(1); 
convert_and_send(0x07); //day 
msec_wait(1); 
convert_and_send(0x08); //year 
msec_wait(1); 
RESET_=0; 
msec_wait(10); 

RESET_=1; 
msec_wait(1); 
convert_and_send(0x8E); //SETS THE WP BIT AS ONE 
msec_wait(1); 
convert_and_send(0x80); 
RESET_=0; 

RED_LED=1; //BOTH LED's TURN OFF WHEN THE RTC TIME HAS BEEN SET 
YELLOW_LED=1; 

while(1) 
{ 
RED_LED=0; //This shows that only the while loop is running and system is waiting for command(REGISTER ADDRESS) 
msec_wait(500); 
if(serial_storage!=0x00) 
{ 
RED_LED=1; //This shows that the serial_storage has the character 
RESET_=1; 
convert_and_send(serial_storage); //sending the address of the register that we want to read from 
msec_wait(1); 
display=receive_convert(); //putting the read DATA_IO into display 
RESET_=0; 
SBUF=display; //sending the read DATA_IO serially to the computer 
msec_wait(2); 
display=0x00; 
} 
else 
{ 
RED_LED=1; 
msec_wait(500); 
} 
} 

}