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  • Connect a SD/SDIO/MMC-Card-Socket to a Trizeps

    Applies to: Trizeps IV(M), Trizeps IV WL, Trizeps V, Trizeps VI.
    See also: SD/SDIO/MMC.

    Schematic

    Typical connection of a SD-Card Slot

    This is the typical SD-Card-Slot schematic used on almost all of our baseboards: ConXS, uConXS, iPAN7.

    (tap to enlarge pictue)

    uSD-Card Slot without Card- and Write- Protect

    This is the minimum configuration for a SD-Card-Slot. Check with Seco wether leaving the SDIO_CARD_DETECT-signal floating is supported by the BSP. Otherwise you need to connect SDIO_CARD_DETECT with a pull-up to 3.3V. The big disadvantage is, that you can't add or remove cards while the OS

    (tap to enlarge pictue)

    SD-Card Slot connection when long signal traces used

    This is a schematic for a SD-Card-Slot which is far away from the SODIMM-socket. i.e. the i-PAN7 Connector Board.

    (tap to enlarge pictue)

    Signals

    Signal-Name

    SODIMM-Pin

    Remark

    Signal-Name

    SODIMM-Pin

    Remark

    SDIO_CMD

    190

    add pull-up(10K..100K). This must have a smaller pull-up than SDIO_DATx-signals do.

    SDIO_CLK

    47

     

    SDIO_DAT0

    192

    add pull-up(10K..100K)

    SDIO_DAT1

    81

    add pull-up(10K..100K)

    SDIO_DAT2

    85

    add pull-up(10K..100K)

    SDIO_DAT3

    51

    add pull-up(10K..100K)

    SDIO_CARD_DETECT

    59

    Connect in a way, that pin is high(3.3V) when card is inserted and low (0V) when card is removed. Note that other SD-card-sockets may have different ways how to handle their COMM, CD and WP pins.

    SDIO_WRITE_PROTECT

    (any gpio)

     

    A 100nF capacitor must be placed near the SDIO-card-socket pins VDD, VSS1, VSS2.