MC24LC256 Not functioning at all

Gibith

I'm trying to simply store bytes on a MC24LC256 EEPROM. I tried using the the test and demo programs that comes with the Appnote associated with this EEPROM, and none of them seemed to work. When I run MC24LC256Demo I get the introduction text but nothing after that. It's the same for the MC24LC256Test program, I get the introduction text but nothing after that. I'm at a complete loss. I'm going to check my wiring again as well.

Thanks

Gibith

I think my problem is that I'm not using a pull up resistor on the SDA. How do I wire that? I've got my javelin on a board of education.

Thanks

Peter Verkaik

You·need pullup resistors on both SDA and SCL line.
Connect one side of the resistor to the pin and the other side
of the resistor to the 5V supply.
Also make sure the javelin ground (aka GND or VSS) is connected
to the eeprom ground.

regards peter

Gibith

That sorta worked. It now finishes the test but of the two eeproms that I have tried, both of them failed the tests. However, since I didn't have any 2k Ohm resistors that the data sheets suggested I used 2.2k Ohm resistors. I figured the extra 200 Ohms wouldn't matter. But seeing as how it doesn't work maybe it does matter.

Peter Verkaik

What program do you use to test?
Depending on eeprom capacity, there must
be 1 or 2 address bytes send. Your eeprom
version requires 2 address bytes. If the test program
only sends 1 address byte (by only testing the
first 256 addresses) then the test would fail.
In that case you must insert a writebyte command
sending the highbyte of a 16bits address.

regards peter