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.
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uSD-Card Slot without Card- and Write- Protect
This is the minimum configuration for a SD-Card-Slot. Check with Keith & Koep 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 is running.
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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.
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Signals
| 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.
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