EEPROM confusion

studiofish

In the Propeller Demo Board Rev D/E/F Schematic (1), the EEPROM is shown as a 25LC256-I/ST. It has a two-wire serial interface and three address lines. This is confirmed by the propeller manual (2).

When I looked for the pin-out on Microchip's website (3), however, the 25LC256-I/ST described there has a three-wire serial interface with hold and chip select lines but no address lines.

I want to build my first propeller project and need the external EEPROM but don't now know which chip to use.

I've searched this forum for 25LC256 but found no matching posts. I've googled "parallax propeller 25lc256" and read every result that I can translate but didn't find
anything helpful.

Can anyone tell me why the two chips with the same number seem to differ so considerably and which chip I should use with the Propeller?

Thanks in advance,

fish

References:
1. www.parallax.com/Portals/0/Downloads/docs/prod/prop/PropDemoDschem.pdf
2. www.parallax.com/Portals/0/Downloads/docs/prod/prop/WebPM-v1.1.pdf
3. ww1.microchip.com/downloads/en/DeviceDoc/21822F.pdf

Bob Lawrence (VE1RLL)

32KB I2C EEPROM

From the Parallax Store:
www.parallax.com/Store/Microcontrollers/PropellerComponents/tabid/785/CategoryID/87/List/0/Level/a/ProductID/400/Default.aspx?SortField=ProductName%2cProductName

32K-byte EEPROM Datasheet (.pdf)
http://www.parallax.com/Portals/0/Downloads/docs/prod/oem/24LC256.pdf


32K-byte EEPROM Schematic (.pdf)
www.parallax.com/Portals/0/Downloads/docs/prod/oem/24LC256schem.pdf

Post Edited (Bob Lawrence (VE1RLL)) : 8/14/2009 7:34:27 PM GMT

studiofish

Thanks, Bob - I've been a bit of a dork, I'm afraid. <slinks away with tail between legs>

f

Bob Lawrence (VE1RLL)

I just updated the links again. Good luck with your project. [noparse]:)[/noparse]

Post Edited (Bob Lawrence (VE1RLL)) : 8/15/2009 12:17:06 AM GMT