You will find that you can only write to it in 512 byte chunks using SPI
mode.  The transfer speed drops considerably when in SPI mode.
The faster, MMC mode requires a lot more code to implement, and is possibly
beyond even  the capabilities of a PIC16F8xx.
Other than that, it's OK.  Beware of Sandisk documentation, there are a
couple of fundamental errors re timing in the set I had. Like saying
"falling edge" when they mean "rising edge"!!
Use the timing diagrams - they are correct, and make sure you read, re-read
and set up the SPI registers - clock, polarity, when data should be read
etc - how the MMC card needs it.
Rgds
Les

-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Erik Kauppi
Sent: 25 January 2002 20:00
To: PICLIST@MITVMA.MIT.EDU
Subject: [PIC]: PIC with MMC memory card?


I'm starting on a design with PIC16F876 and
an MMC (MultiMediaCard) memory card.  The MMC looks
like a fairly straighforward SPI synchronous serial device,
not so different conceptually from the 8-pin EEPROMs we all use.

Except of course that it's removable, and available
in 8Mbyte to 64Mbyte sizes.  A PIC with 64 meg, wow!

Anyway, has anybody been down this path?  Tips
or suggestions or gotcha's?


---- Erik Kauppi ekauppi@corsa-inst.com (734) 761-1545 ---
---- Corsa data acquisition: http://www.corsa-inst.com----

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