1 Reply Latest reply on Apr 20, 2015 12:11 AM by Madhu Lakshmipathy

    about SD clk (2)

    @gmail.com

        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.