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3.2.3.6 SDI/O interface signals
As previously told in paragraph 3.2.2, 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 #1 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 +3.3V_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 +3.3V_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_LED: LED output signal, electrical level +3.3V_S. It is used to drive an external LED when there are transfers on SD Bus.
SDIO_WP: Write Protect bidirectional signal, electrical level +3.3V_S. It is used to communicate the status of Write Protect switch on external SD/MMC card.
SDIO_PWR#: SD power enable, tied to GND through a 47kΩ pull-down resistor.
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.
3.2.3.7 Audio interface signals
Q7-928 module supports AC'97 audio format, thanks to native support offered by the processor to this audio codec standard.
Both AC'97 Fixed and variable mode are supported, min frame rate 8kHz, max Frame rate 48kHz
Here following the signals related to Audio AC'97 interface:
HDA_SYNC: AC'97 Serial Bus Synchronization. Output from the module to the Carrier board, electrical level +3.3V_S.
HDA_RST#: AC'97 Codec Reset. Active Low signal Output from the module to the Carrier board, electrical level +3.3V_S.
Q7-928
Q7-928 User Manual - Rev. First Edition: 1.0 - Last Edition: 3.0 - Author: S.B. - Reviewed by P.Z Copyright © 2016 SECO S.r.l.
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