about SD clk (2)

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Anonymous
Not applicable

  Hello

   

 

   

I wrote post about SD clk several day ago (http://www.cypress.com/?app=forum&id=167&rID=110967)

   

I head something of the thread, but I still can't solve it.

   

I tested two class of SD card made by Transcend. for one ting is Class 10, for another thing is UHS-1(x300)

   

I set a gpio for working 1.8v on the board. there are two SD card is not working.

   

SD clk works only 400Khz.

   

but I tested another SD card made by SAMSUNG. the sd card is working on the 1.8V

   

so I tested SDR mode and DDR mode. but SD clk working 50.4 Mhz Fixed.

   

This is result of the test.

   

 

   

VIO2/VIO3 is 3.3V, DDR mode: 14MB/s read. The clk works 50.4 Mhz.

   

VIO2/VIO3 is 3.3V, SDR mode: 14MB/s read. The clk works 50.4 Mhz.

   

 

   

VIO2/VIO3 is 1.8V, DDR mode: 14MB/s read. The clk works 50.4 Mhz.

   

VIO2/VIO3 is 1.8V, SDR mode: 14MB/s read. The clk works 50.4 Mhz.

   

 

   

 

   

The result is no changed to change Voltage or SDR/DDR mode.

   

What I miss it ???

   

 

   

Thank you

   

Regards.

   
        
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1 Reply
Anonymous
Not applicable

 Hi, 

   

Please find the updated response in the orginal Thread.

   

Regards,

   

- Madhu Sudhan

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