Seco Qseven Q7-C26 User Manual page 39

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3.2.17

SD interface signals

The NXP i.MX8 processors include an Ultra Secured Digital Host Controller (uSDHC), providing the interface between the host system and an SD card.

Such an SD controller complies with SD Host Controller Standard Specification version 2.0

The SD port is externally accessible through the golden edge finger connector, and can work in 1-bit and 4-bit mode.

Signals involved with SD interface are the following:

SDIO_PWR#: SD power enable. Active Low Output signal, electrical level +3.3V_RUN. This signal can be used on the Carrier board to enable the power line for the

SD card.

SDIO_CD#: Card Detect Input. Active Low Signal, electrical level +3.3V_RUN. This signal must be externally pulled low to signal that a SD Card Device is present.

SDIO_CLK: Clock Line (output), 50MHz maximum frequency for High Speed Mode.

SDIO_CMD: Command/Response line. Bidirectional signal, electrical level +3.3V_RUN, used to send command from the Host to the connected card, and to send

the response from the card to the Host.

SDIO_WP: Write Protect input, electrical level +3.3V_RUN. It is used to communicate the status of Write Protect switch of the external SD card. Since microSD cards

the card as protected from writing.

SDIO_DAT[0÷3]: SD Card data bus. SDIO_DAT0 signal is used for all communication modes. SDIO_DAT[1÷3] signals are required for 4-bit communication mode.

3.2.18

Power Management and Control signals

According to Qseven® specifications, on the golden edge finger connector there is a set of signals that are used to manage the power rails and power states.

The signals involved are:

PWGIN: Power Good Input, +5V_RUN tolerant active high signal. It must be driven on the carrier board to signal that power supply section is ready and stable. When

this signal is asserted, the module will begin the boot phase. The signal must be kept asserted for all the time that the module is working. This signal is managed by

the on-board STM32 Embedded Controller.

PWRBTN#: Power Button Input, active low, +3.3V_ALW

button: a pulse to GND of this signal will switch power supply On or Off. This signal is managed by the on-board STM32 Embedded Controller.

RSTBTN#: Reset Button Input, active low, +3.3V_ALW

to GND of this signal will reset the Qseven® module. This signal is managed by the on-board STM32 Embedded Controller.

BATLOW#: Battery Low Input, active low, +3.3V_ALW

battery is low, or that some battery-related event has occurred. Can be left unconnected if not used. This signal is managed by the on-board STM32 Embedded

Controller.

WAKE#: Wake Input, active low +3.3V_ALW

Wake-up event has occurred, and consequently the module must turn itself on. It can be left unconnected if not used. This signal is managed by the on-board

STM32 Embedded Controller.

SUS_S3#: S3 status output, active low, +3.3V_ALW electrical voltage signal. This signal must be used, on the carrier board, to shut off the power supply to all the

Q7-C26

Q7-C26 User Manual - Rev. First Edition: 1.0 - Last Edition: 1.0

-up resistor. When working in ATX mode, this signal can be connected to a momentary push-

-up resistor. This signal can be connected to a momentary push-button: a pulse

-up resistor. This signal can be driven on the carrier board to signal that the system

-up resistor. This signal can be driven low, on the carrier board, to report that a

GND, otherwise the OS will always consider

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