Seco Q7-A75-J User Manual page 26

3.2.1.5 SDI/O interface signals
The NXP i.MX6 processors offer many different SDIO interfaces, that can be used independently one from the other to implement different mass storages (internal
eMMC, internal SD Card, external SDI/O interface).
Each of the uSDHC controllers complies with:
SD Host Controller Standard Specification version 3.0
MMC System Specification version 4.2/4.3/4.4/4.41
SD Memory Card Specification version 3.0 and supports the Extended Capacity SD Memory Card
SDIO Card Specification version 3.0
SDI/O port #4 is externally accessible through golden edge finger connector, and can work in 1-bit, 4-bit and 8-bit modes (8-bit mode for MMC support).
Signals involved with SDI/O interface are the following:
SDIO_CD#: Card Detect Input. Active Low Signal, electrical level +3P3V_S with 10kΩ pull-up resistor. This signal must be externally pulled low to signal that a
SDIO/MMC Card is present.
SDIO_CLK: Clock Line (output), 52MHz maximum frequency for MMC High Speed Mode, 50 MHz maximum frequency for SD/SDIO High Speed Mode
SDIO_CMD: Command/Response line. Bidirectional signal, electrical level +3P3V_S, used to send command from Host (i.MX6 processor) to the connected card,
and to send the response from the card to the Host.
SDIO_PWR#: SDIO Power Enable output, active low signal, electrical level +3P3V_S. It is used to enable the power line supplying SD/SDIO/MMC devices.
SDIO_WP: Write Protect bidirectional signal, electrical level +3P3V_S. It is used to communicate the status of Write Protect switch on external SD/MMC card.
SDIO_DAT[0÷7]: SDIO data bus. SDIO_DAT0 signal is used for all communication modes. SDIO_DAT[1÷3] signals are required for 4-bit SD/SDIO/MMC
communication modes. SDIO_DAT[4÷7] are used only for 8-bit MMC communication mode.
All of the above mentioned signals can also be used for different functionalities; please refer to the pin muxing table for more details.
μQ7-A75-J
μQ7-A75-J User Manual - Rev. First Edition: 1.0 - Last Edition: 1.0 - Author: S.B. - Reviewed by P.Z. - Copyright © 2016 SECO S.r.l. 26