> I'm trying to use a MultiMedia Memory Card from
> Sandisk. I'm trying to use it in the SPI mode.
> Can the CS line be low all the time?

I think so.  I'm using it in MMC mode, but a quick scan of the spec
does not show any place where it must be cycled high.

Be careful that you send the CMD0 with CORRECT CRC, becuase
the MMC is in native MMC mode until the CMD0 is sent with CS low.
After the CMD0, the card switches to SPI mode and the CRCs are
"don't care" (unless you turn them on).

Hex code for CMD 0 is always: 40 00 00 00 00 95

Octavio, what socket are you using for the MMC?  Who supplies it?

Regards,

Barry.
------------
Barry King, Engineering Manager
NRG Systems "Measuring the Wind's Energy"
www.nrgsystems.com
Phone: 802-482-2255
FAX:   802-482-2272