Redpic
Joined: 18 Dec 2005
Posts: 5
Location: Spain
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| 4 x Serial EEPROM 24AA1025 512 Kbytes direct access driver. |
 Posted: Sun Oct 15, 2006 10:32 am |
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This work is based in two previous works:
The EX_EXTEE.C from CCS C examples directory and
a post in this same Code Library section Driver Microchip 24AA512 512k I2C EEPROM by UFAnders
This driver is capable for addresing from 0x0000 to 0x7FFFF, 0x8000 positions = 512 Kbytes.
Driver:
| Code: |
///////////////////////////////////////////////////////////////////////////////
//
// 4 x EEPROM 24AA1025 Driver with absolute memory addressing
//
///////////////////////////////////////////////////////////////////////////////
#define EEDEBUG
// device hardware address
int8 const deviceAddress1 = 0b00000011; // #3
int8 const deviceAddress2 = 0b00000010; // #2
int8 const deviceAddress3 = 0b00000001; // #1
int8 const deviceAddress4 = 0b00000000; // #0
// baseAddress = 8 bits which mean ...
//
// Fixed (4 bits) -> 1010
// EE internal Block (1 bit) -> 0 for 0000/FFFF, 1 for 10000/1FFFF
// Dev Hard Address (2 bits) -> 00 or 01 or 10 or 11
// R/W (1 bit) -> 0 -> Write / 1 -> Read
int8 const baseAddress24AA1025 = 0b10100000;
// Aux Functions //////////////////////////////////////////////////////////////
int1 menRelative2BankSelect(int32 memRelativeAddress){
int1 returnBit=0;
if(memRelativeAddress>(int32) 0xffff) returnBit = 1;
return returnBit;
}
int32 memAbsoluteAddress2menRelativeAddress(int8 deviceOrder, int32 memAddress){
int32 returnInt32 = 0;
switch(deviceOrder){
case 1: returnInt32 = memAddress;
break;
case 2: returnInt32 = memAddress - 0x20000;
break;
case 3: returnInt32 = memAddress - 0x40000;
break;
case 4: returnInt32 = memAddress - 0x60000;
break;
}
return returnInt32;
}
int8 memAbsoluteAddress2deviceOrder(int32 memAddress){
int8 returnByte=0;
if((memAddress>0x05ffff) && (memAddress < 0x080000)) returnByte=4;
if((memAddress>0x03ffff) && (memAddress < 0x060000)) returnByte=3;
if((memAddress>0x01ffff) && (memAddress < 0x040000)) returnByte=2;
if((memAddress< 0x020000)) returnByte=1;
return returnByte;
}
int8 memAbsoluteAddress2deviceAddress(int32 memAddress){
int8 deviceOrder=0, returnByte=0;
deviceOrder = memAbsoluteAddress2deviceOrder(memAddress);
switch(deviceOrder){
case 0: returnByte = 0xff;
break;
case 1: returnByte = deviceAddress1;
break;
case 2: returnByte = deviceAddress2;
break;
case 3: returnByte = deviceAddress3;
break;
case 4: returnByte = deviceAddress4;
break;
}
return returnByte;
}
// Main Functions /////////////////////////////////////////////////////////////
void writeByte24AA1025(int32 memAddress, int8 data){
int8 baseAddress;
int8 deviceAddress;
int8 deviceOrder=0;
int32 memRelativeAddress;
int8 bank=0;
deviceAddress = memAbsoluteAddress2deviceAddress(memAddress);
deviceOrder = memAbsoluteAddress2deviceOrder(memAddress);
memRelativeAddress = memAbsoluteAddress2menRelativeAddress(deviceOrder, memAddress);
bank = menRelative2BankSelect(memRelativeAddress);
baseAddress = baseAddress24AA1025 + (bank<<3) + (deviceAddress<<1);
#ifdef EEDEBUG
printf("\r\n\nAbsolute Address: %LX Relative Address: %Lx Device: %u Bank: %u\r\n",memAddress,memRelativeAddress,deviceOrder,bank);
#endif
i2c_start();
i2c_write(baseAddress);
i2c_write(memRelativeAddress>>8);
i2c_write(memRelativeAddress);
i2c_write(data);
i2c_stop();
delay_ms(5);
}
int8 readByte24AA1025(int32 memAddress){
int8 returnByte=0;
int8 baseAddress;
int8 deviceAddress;
int8 deviceOrder=0;
int32 memRelativeAddress;
int8 bank=0;
deviceAddress = memAbsoluteAddress2deviceAddress(memAddress);
deviceOrder = memAbsoluteAddress2deviceOrder(memAddress);
memRelativeAddress = memAbsoluteAddress2menRelativeAddress(deviceOrder, memAddress);
bank = menRelative2BankSelect(memRelativeAddress);
baseAddress = baseAddress24AA1025 + (bank<<3) + (deviceAddress<<1);
#ifdef EEDEBUG
printf("\r\n\nAbsolute Address: %LX Relative Address: %Lx Device: %u Bank: %u\r\n",memAddress,memRelativeAddress,deviceOrder,bank);
#endif
i2c_start();
i2c_write(baseAddress);
i2c_write(memRelativeAddress>>8);
i2c_write(memRelativeAddress);
i2c_start();
i2c_write(baseAddress|1);
returnByte = i2c_read(0);
i2c_stop();
return returnByte;
}
///////////////////////////////////////////////////////////////////////////////
|
Adapted from example code EX_EXTEE.C, my own EEPROM_24AA1025x4.C:
| Code: |
///////////////////////////////////////////////////////////////////////////////
//
// EEPROM_24AA1025x4.C
//
// based on EX_EXTEE.C example by CCS
// and "Microchip 24AA512 512k I2C EEPROM driver" by UFAnders
// in http://www.ccsinfo.com/forum/
//
// by RedPic from http://picmania.garcia-cuervo.com
//
// October 2006
//
///////////////////////////////////////////////////////////////////////////////
#include <18F4550.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#use i2c(master, sda=PIN_B0, scl=PIN_B1)
#include <input.c>
#include <24AA1025x4.c>
const char Version[]="1.0.F\0";
///////////////////////////////////////////////////////////////////////////////
//
// Main
//
///////////////////////////////////////////////////////////////////////////////
void main() {
BYTE value, cmd;
int32 address;
int8 device;
delay_ms(300);
printf("\r\n\n");
printf("[RRBOARD2] EEPROM Commander %s\r\n",version);
printf("based on 24AA1025 Microchip Hardware\r\n");
printf("\xa9 10.2006 by RedPic\r\n\n");
do {
do {
printf("\r\nDo you Read or Write? : ");
cmd=getc();
cmd=toupper(cmd);
putc(cmd);
} while ( (cmd!='R') && (cmd!='W') );
printf("\n\rGive me EEPROM internal absolute Address (24 bits) in hex : ");
address = gethex();
address = (address<<8)+gethex();
address = (address<<8)+gethex();
device = memAbsoluteAddress2deviceAddress(address);
if(cmd=='R')
printf("\r\nReturn Value (8 bits) in hex is : %X\r\n",readByte24AA1025(address));
if(cmd=='W') {
printf("\r\nEnter new value (8 bits) in hex : ");
value = gethex();
printf("\n\r");
writeByte24AA1025(address, value );
}
} while (TRUE);
}
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At last a executing view:
More details (in spanish) in AUX Quad-EEPROM I2C 512 Kbytes de EEPROM con cuatro 24AA1025 |
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