ds2430.c

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/*
  CodeVisionAVR C Compiler
  (C) 1998-2004 Pavel Haiduc, HP InfoTech S.R.L.

  Dallas Semiconductor DS2430 1 Wire bus EEPROM functions
*/

#include <delay.h>

// selects a specific DS2430 on the bus
// if romcode is NULL then only one 1 Wire device can be used
unsigned char ds2430_select(unsigned char *romcode)
{
unsigned char i;
if (!w1_init()) return 0;
if (romcode)
   {
   w1_write(0x55);
   for (i=0;i<8;i++) w1_write(*romcode++);
   }
else return w1_write(0xCC);
}

// read a block of size bytes starting from memory address addr
// and stores it at dest
// returns 1 if succesful, 0 if not
unsigned char ds2430_read_block(unsigned char *romcode,
unsigned char *dest,unsigned char addr,unsigned char size)
{
// read EEPROM contents to scratchpad and
// read the scratchpad contents
if (!ds2430_select(romcode)) return 0;
w1_write(0xF0);
if (!w1_write(addr)) return 0;
while (size--) *dest++=w1_read();
return 1;
}

// read a byte from memory address addr and stores it at data
// returns 1 if succesful, 0 if not
unsigned char ds2430_read(unsigned char *romcode,
unsigned char addr,unsigned char *data)
{
return ds2430_read_block(romcode,data,addr,1);
}

// write a block of size bytes, located at source,
// starting from memory address addr
// returns 1 if succesful, 0 if not
unsigned char ds2430_write_block(unsigned char *romcode,
unsigned char *source,unsigned char addr,unsigned char size)
{
unsigned char i;
unsigned char *p;
p=source;
// read EEPROM's contents to the scratchpad               
if (!ds2430_select(romcode)) return 0;
w1_write(0xF0);
// write new data to the scratchpad
if (!ds2430_select(romcode)) return 0;
w1_write(0x0F); 
w1_write(addr);
for (i=0;i<size;i++) w1_write(*p++);
// verify that the new data written in the scratchpad is correct
if (!ds2430_select(romcode)) return 0;
w1_write(0xAA);
w1_write(addr);
for (i=0;i<size;i++)
    if (w1_read()!=*source++) return 0;
// copy the scratchpad to the EEPROM
if (!ds2430_select(romcode)) return 0;
w1_write(0x55);
if (!w1_write(0xA5)) return 0;
// wait for the write process to complete
delay_ms(15);
return 1;
}

// write the byte data at memory address addr
// returns 1 if succesful, 0 if not
unsigned char ds2430_write(unsigned char *romcode,
unsigned char addr,unsigned char data)
{
return ds2430_write_block(romcode,&data,addr,1);
}

// read a block of size bytes, starting from application
// register address addr and stores it at dest
// returns 1 if succesful, 0 if not
unsigned char ds2430_read_appreg_block(unsigned char *romcode,
unsigned char *dest,unsigned char addr,unsigned char size)
{
// reads the data from the scratchpad
if (!ds2430_select(romcode)) return 0;
w1_write(0xC3);
if (!w1_write(addr)) return 0;
while (size--) *dest++=w1_read();
return 1;
}

// write a block of size bytes, located at source,
// starting from application register address addr
// returns 1 if succesful, 0 if not
unsigned char ds2430_write_appreg_block(unsigned char *romcode,
unsigned char *source,unsigned char addr,unsigned char size)
{
unsigned char i;
unsigned char *p;
p=source;
// read the data from the status register
if (!ds2430_select(romcode)) return 0;
w1_write(0x66);
w1_write(0);
// check if the application register is locked
if (w1_read()==0xFC) return 0;
// read application register's contents to the scratchpad               
if (!ds2430_select(romcode)) return 0;
w1_write(0xC3);
// write new data to the scratchpad
if (!ds2430_select(romcode)) return 0;
w1_write(0x99); 
w1_write(addr);
for (i=0;i<size;i++) w1_write(*p++);
// verify that the new data in the scratchpad is correct
if (!ds2430_select(romcode)) return 0;
w1_write(0xC3);
w1_write(addr);
for (i=0;i<size;i++)
    if (w1_read()!=*source++) return 0;
// copy & lock the application register
if (!ds2430_select(romcode)) return 0;
w1_write(0x5A);
if (!w1_write(0xA5)) return 0;
// wait for the write process to complete
delay_ms(15);
return 1;
}