C Code for interafaing EPROM in PIC 16F87X

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eeprom.h

(263 Bytes) Downloaded 448 times

#include <pic.h>

/*

R/W eeprom on PIC16F87x

example:

main()
{
my_eeprom_write(addr,data);
if (my_eeprom_read(EEPROM_FORMAT_IN_PROGRESS)==TRUE) etc;
}



*/


void my_eeprom_write(unsigned char addr, unsigned char value)
{
//see 'writing to eeprom memory' in PIC16F876 manual

static bit gie_temp;

EEIF=0; //this is necessary in case this EEPROM write
//was preceded by a program memory write
EEADR=(unsigned char)(addr);
EEDATA=(unsigned char)(value);
EEPGD=0; //write to EEPROM, not data memory
gie_temp=GIE; //save the status of GIE
WREN=1; //enable writes
GIE=0;
EECON2=0x55;
EECON2=0xAA;
WR=1;
while (!EEIF)
{
//do nothing - wait WR to be cleared in hardware
}
EEIF=0; //so it wont trigger false interrupts
WREN=0; //disable writes
GIE=gie_temp; //restore GIE to previous value
}

#define MY_EEPROM_READ(addr) \
\
( (EEADR=((unsigned char)(addr))), \
(EEPGD=0), \
(RD=1), \
((unsigned char)EEDATA) )

unsigned char my_eeprom_read(unsigned char addr)
{
EEADR=(unsigned char)addr;
EEPGD=0;
RD=1;
return (unsigned char)EEDATA;
}

unsigned int my_eeprom_read_int(unsigned char addr)
{
return ((unsigned int)(eeprom_read(addr)) | ((unsigned int)((unsigned int)(eeprom_read((unsigned char)(addr+1)))<<8)));
}

void my_eeprom_write_int(unsigned char addr, unsigned int data)
{
eeprom_write(addr,(unsigned char)(data & 0xFF));
eeprom_write((unsigned char)(addr+1),(unsigned char)(data>>8));
}