2008-03-17 10:53:25     about spi/mmc card read/write speed?

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2008-03-17 10:53:25     about spi/mmc card read/write speed?

浩 何 (CHINA)

Message: 52587   

 

hello:

 

    i have test the spi/mmc card speed  :    cp  /bin   /usr/spi_mmc -rf

 

it's about (1.6-2)Mbit/s,  i'll ask a question , what 's the highest  speed of  the spi/mmc write!

 

Another question:

 

Does the spi/mmc  driver in  /linux-2.6.x/driver/mmc/spi_mmc   support 2GB, 4GB  SD card   in VFAT filesystem

 

if support, which version i 'll   download

 

thanks!!!!

 

 

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2008-03-17 12:38:09     Re: about spi/mmc card read/write speed?

Mike Frysinger (UNITED STATES)

Message: 52591    the highest speed you could possibly achieve is limited by the speed of the SPI bus ... it tops out at SCLK / 4 (so typically ~25mhz)

 

as for filesystems, you're asking a question about technologies which are not dependent on the other ... filesystems do not care what block device they sit on top of, so of course the spi mmc driver supports anything because it doesnt care ... it only transfers blocks of data; it's up to higher levels to interpret those blocks

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