[SOLVED] how to address an eeprom...

[Sudhp]

hii.

I am working on EEPROM 24c16.......
my programming to write a byte to EEPROM is....(download from net)

void save()					//save in EEPROM
        {	
	start();
	send_byte(0xA0);						//device address
	aknowledge();
	send_byte(0x00);						//word address
	aknowledge();
	                        		       //send data
	send_byte(hour1);
	aknowledge();
	send_byte(min1);
	aknowledge();
	send_byte(sec1);
	aknowledge();
	send_byte(hour2);
	aknowledge();
	send_byte(min2);
	aknowledge();
	send_byte(sec2);
	aknowledge();
	stop();
	}

I just wanna know how addressing of word address is done ?....
and how much data I can store to this word address....
and how can I address next word address(if possible).........

 

[babar_ali]

Hello!

Answer of all of the above questions are present in datasheet.:|

Enjoy!!!

 

[jayanth.devarayanadurga]

You have to send 2 bytes for address if larger eeproms are used. Send address byte, send data address high, send data address low...

 

[Sudhp]

Hello!

Answer of all of the above questions are present in datasheet.:|

Enjoy!!!

Hii babar...
I don't get u.....
what r u exactly wanna say......

- - - Updated - - -

You have to send 2 bytes for address if larger eeproms are used. Send address byte, send data address high, send data address low...

Thanks...
I exactly wanna know about this line....

send_byte(0x00); //word address
aknowledge();

why this line is used.....and it holds which address.....

 

[jayanth.devarayanadurga]

This is the device address. The eeprom will have three address pins A0, A1, A2. If they are all grounded then address is 0b000 and it is written as 0x00. It is device address and not address of memory location.

 

[Sudhp]

This is the device address. The eeprom will have three address pins A0, A1, A2. If they are all grounded then address is 0b000 and it is written as 0x00. It is device address and not address of memory location.

Thanks for reply......
but 0xA0 is also used for the device address(studied at net)
as 1 0 1 0 A1 A2 A3 R/W (r/w=0 for write operation and r/w=1 for read )
here A1,A2,A3 r zero...
so device address is 0xA0.....
if 0x00 is used for device address thn why 0xA0 is used....
waiting for reply.......thanks again

 

[nick703]

The memory size of the 24C16 is 16k bits (!) which makes 2k bytes. They are organised in 128 pages with 16 bytes each. The upper three page address(A0..A2) bits are transferred together with the slave address (which is 0xA0 for writing and 0xA1 for reading).

 

[Sudhp]

The memory size of the 24C16 is 16k bits (!) which makes 2k bytes. They are organised in 128 pages with 16 bytes each. The upper three page address(A0..A2) bits are transferred together with the slave address (which is 0xA0 for writing and 0xA1 for reading).

Thanks for the reply.....
24c16 has 2 K bytes memory space.....
can I use all 2 K byte space using same program....

 

[jayanth.devarayanadurga]

Sorry, address byte is sent in this format. 1 0 1 0 A1 A2 A3 R/W.

 

[Sudhp]

Sorry, address byte is sent in this format. 1 0 1 0 A1 A2 A3 R/W.

thanks.......
It will help me a lot.....
Tell me one thing more....
If I hav to interface one more eeprom than what address I will give to that.....and How....

 

[Raady Here]

Thanks for the reply.....
24c16 has 2 K bytes memory space.....
can I use all 2 K byte space using same program....

Yes you use in one single program if you want to use it.

 

[jayanth.devarayanadurga]

Connect another eeprom A0 to +5V and A1 and A2 to ground so it willl have value 0x01

Use address bytes

1 0 1 0 A0 A1 A2 R/W (r/w=0 for write operation and r/w=1 for read )

1 0 1 0 A0 A1 A2 R/W (r/w=0 for write operation and r/w=1 for read )

1 0 1 0 1 0 0 R/W (r/w=0 for write operation and r/w=1 for read )

1 0 1 0 1 0 0 R/W (r/w=0 for write operation and r/w=1 for read )

 

[Sudhp]

Connect another eeprom A0 to +5V and A1 and A2 to ground so it willl have value 0x01

Use address bytes

1 0 1 0 A0 A1 A2 R/W (r/w=0 for write operation and r/w=1 for read )

1 0 1 0 A0 A1 A2 R/W (r/w=0 for write operation and r/w=1 for read )

1 0 1 0 1 0 0 R/W (r/w=0 for write operation and r/w=1 for read )

1 0 1 0 1 0 0 R/W (r/w=0 for write operation and r/w=1 for read )

thanks.....

- - - Updated - - -

EEPROM store the data in hex format......
when we take the data from eeprom then data has which format......

 

[jayanth.devarayanadurga]

All data are stored in binary format. You can wrote data as binary, hex, decimal in your program. when data is written to eeprom memory cells turn ON or OFF depending upon the bit value.

 

[Sudhp]

All data are stored in binary format. You can wrote data as binary, hex, decimal in your program. when data is written to eeprom memory cells turn ON or OFF depending upon the bit value.

I have to know about these things.....
can u suggest me any book or send me any link......

 

[jayanth.devarayanadurga]

Refer to books

"8051 Microcontroller and Embedded Systems: Using Assembly and C"

"PIC Microcontrollers and Embedded Systems: Using Assembly and C"

"AVR Microcontrollers and Embedded Systems: Using Assembly and C"

by Muhammad Ali Mazidi and others.