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How to interface flash memory cards to microcontroller for external memory excess?

Started by partha pabbu August 1, 2006
hi friends,
Can you plz gude for this question.
How to interface flash memory cards to microcontroller for external memory excess?
Thank you
chaitanya


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Can you plz gude for this question. How to interface flash memory cards to microcontroller for external memory excess?
====================================Usually they have a serial interface that uses a clock line and a data line. Most microcontrrollers have an SPI interface that automatically shifts out the clock and data, but it is also possible to write a subroutine that shifts each bit out and sets the clk line hi then lo for each bit (usually called 'bitbanging'). So just study the data sheet for the memory card and the microcontroller to see which lines need to connect to what on the memory card, then write subroutines to so the low level read write functions described in the datashett... read a sector, write a sector... usually just a loop of reading or writing 524 bytes, or however many bytes in the memory card block. Sound easy so far?
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On Tue, Aug 01, 2006 at 01:08:18PM -0400, B...@aol.com wrote:
> > Can you plz gude for this question. How to interface flash memory
> > cards to microcontroller for external memory excess?
> ====================================> Usually they have a serial interface that uses a clock line and a data
> line.

That is true for many FLASH storage chips such as the Atmel AT45DB011.
FLASH memory cards such as Compact Flash have a parallel bus interface
which is a 50 pin version of PCMCIA which is similar to a 16 bit ISA bus
but with working hot swap and plug-and-play.

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