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Altera_Forum
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14 years ago

Speed of SPI core problem

Hi I have generated a uClinux kernel for my DE0 board,and I use the IP core of SD card is SPI core with 30MHz clock (According to http://www.alterawiki.com/wiki/mmcsd). I can opera...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

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Your SPI clock is 25000Hz aka 25kHz, so You get 25Kbps serialized speed or 25/8 = 3.125 KBps, so do the math:

to upload 1.7MB (1700KB) file, You need 1700 / 3.125 = 544 seconds or more than 9 minutes.

Increase the SPI clock at least 100 times, so it should be 2500000Hz or 2.5MHz and do the tests again.

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Sorry I ask stupid question.

I'm really really fool.

The problem is hang me very long time.

Thank you very much for your reply.