Lpc2000

I haven't really followed this thread so I might be missing a point or 
two. We ought to remember that SD cards are not only "Secure Digital" 
capable but usually operate in a 4-bit data transfer mode in most 
high-speed commercial interfaces. It does however support the slower SPI 
mode which is how the MMC cards work although I have never looked into 
the MMC myself.

There are some enhancements to the operation of the SD card over the MMC 
etc but basically they are driven much the same way. MMC is fast being 
replaced if not so already by SD, so I would always gear my efforts 
purely towards SD.

I have never used the crypto feature of the SD as I have never required 
it plus I would need the documents/registration/NDA etc to implement it 
anyway.

MMC = SPI accessed memory
SD  = SPI or 4-bit access crypto/open memory

*Peter*


Tom Walsh wrote:
> I'm getting really confused here.  AFAIK: MMC cards you can purchase 
> don't have the encyrpto capabilities.   While Secure Digital card can 
> have encrypted data, but also can behave as an MMC protocol card.  While 
> I also understand that pure MMC cards do exist, they are becomming very 
> very hard to find???
>
> Here comes the confusion on my part: If I have a Secure Digital / MMC 
> card that is working with my system, but I don't have the encryption 
> information to do the security mode: isn't this, in fact, an MMC Card?
>
> The stickers on the BOX it came in say "SD Memory Card".
>
> Maybe I should just avoid using the term "MMC" altogether??  It sounds 
> to me like a "name game"?
>
> TomW