Yes,

Ramtron have FRAM which is non-volitle.... but you can write at typical "bus-speeds". Conventional EEPROM requires a delay up to 10mS after each byte write (and endurance typically up to 1E6)

So you can use serial FRAM as "RAM" like operation.

Writing endurance is typically 10E12 or more (some are infinite endurance over a 10 year period - see data sheets).

www.ramtron.com

Or specifically serial FRAM
http://www.ramtron.com/doc/Produ...t.asp?ID=5


both SPI and I2C versions.... Up 256kbit versions I think.



Regards
Joe