Andrew Kunz <PICLIST@MITVMA.MIT.EDU> wrote:

> I2C usually has page-write modes (multiple bytes per write
> command).

Andy Warren wrote:

>Most of the SPI EEPROMs do, too.  Personally, I prefer using I2C
>EEPROMs in general... But for this application, I'd probably use a
>93C46, just because the code to access it is smaller and faster.

I've only used the 24LC01, which is an I2C device.  If it is typical,
one should also keep in mind that a write cycle takes upwards of 10ms.
Obviously this can be done in the background if you have other stuff
to do, but if you are looking for "constant" quick access, like ram,
this is VERY slow.
Something that tripped me up for a while with this part is that the
pages in the page-write mode have to be on 8 byte boundaries - you
can't just write the next 8 consecutive bytes.  For instance, if,
using page-write mode, you write 5 bytes starting at address 5, the
data will be written to eeprom addresses 5, 6, 7, 0, 1.
btw, the 10ms is for any size write from 1 to 8 bytes.