EEPROM memory organization - what is the difference?

[Agent24]

Take for example a 256kbit EEPROM.

I can purchase them in both 32K x 8 or 256K x 1 configurations - but what is the difference, and more importantly, does it matter?

When using an EEPROM, will the system care about the organization or not? Is it transparent to the 'user' (other circuitry)? Does only the EEPROM itself care what the organization is?

Can you use a 32K x 8 to replace a 256K x 1? or the other way around?

[mwilson]

Can you give us some example part numbers? I don't see any trace of 265x1 EEPROMS on DigiKey. IIRC somethingx1 memory chips will only have one data pin; somethingx8 have 8 data pins (and, typically, 7 fewer address pins.) On the circuit board, they're not the same at all.

SPI and I2C interface chips will do things differently. Are you thinking of some of those?

[Agent24]

That would be because I wasn't looking on Digikey - they want $50 for shipping to NZ so I've never used them.

I was looking at these parts on RS Components: http://newzealand.rs-online.com/web/c/s ... ck=Density

But yes, you are right - the ICs in question were comparing a parallel to a serial EEPROM. Not a good example!


I can't actually recall the part numbers of the EEPROMs I was thinking of, but I believe one was 256k x 8 bit while the other was 128k x 16 bit. Of course now I'm looking, I can't find anything like that anywhere!

I can find some which seem to have support for both 256k x 8 bit and 128k x 16 bit - so perhaps my question still has a leg to stand on...