SD UHS-I card SPI high speed mode.

Discussion in 'Embedded Systems and Microcontrollers' started by Fransisco Ferreira, Jul 8, 2016.

  1. Fransisco Ferreira

    Thread Starter New Member

    Jul 8, 2016
    4
    0
    Hi,

    i am having issues with getting a UHS-I card to run in SPI high speed mode (50MHz). I have a older class 4 card that works fine on 50MHz but the UHS-I card does not work. According to the simplified SD specs 3.9.1 a UHS-I card must support high speed mode. But cmd6 always returns an error when querying for high speed mode.

    My initialization routine:
    CMD0
    CMD8
    CMD58
    ACMD41
    CMD6

    This always fails on the UHS-I cards i tried (Transcend 16GB & Sandisk 16GB). While the older card switches to high speed mode no problem.

    Does anyone have a clue why this doesnt work?
     
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