CCOMe-C79
CCOMe-C79 - Rev. First Edition: 1.0 - Last Edition: 1.0 - Author: A.R. - Reviewed by E.S. Copyright © 2021 SECO S.p.A.
57
GPIO pin header / microSD Card Slot
According to the release 3.0 of COM Express specifications, on the same pins are
multiplexed the signals necessary for the implementation of 4-bit SD cards with four
General Purpose Inputs plus four general Purpose Outputs. Effective support of
GPI+GPO signals or SDIO interface depends on the module used. Please refer to the
User Manual of the COM Express module used for a detail about the interface
support.
The selection between SD Card interface and GPI/O interface is made using
jumper JP10, according to the table on the left.
If supported by the COM Express module installed on CCOMe-C79,
the GPIO interface, is available on CN31, which is a dual row, 10 pin,
P2.54mm standard pin header, type ADIMPEX p/n LE008210-R, with the pinout
shown in the table on the left. To redirect the signal coming directly from COM
Express module to GPIO header, jumper
GPO[0:3]: General purpose output signals
GPI[0:3]: General purpose input signals
The
33), soldered on bottom side of the
module, push-push type, H=1.68 mm, type JST DM3AT-SF-PEJM5 or equivalent. When this interface
is available, this card slot is accessible with jumper JP10 inserted.
Signals description
SD_CD#: Card Detect Input. This signal is grounded when the card is inserted.
SD_CLK: SD Clock Line (output).
SD_CMD: Command/Response bidirectional line.
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.
GPIO pin header CN31
Pin Signal
Pin Signal
1
GPO0
2
+3.3V_ALW
(with 1.5 resettable fuse)
3
GPO1
4
GPI0
5
GPO2
6
GPI1
7
GPO3
8
GPI2
9
GND
10
GPI3
JP10 position
GPIO/microSD selector
Not inserted
GPIO
Inserted
microSD
μ
SD Card Slot CN33
Pin
Signal
1
SDIO_DAT2
2
SDIO_DAT3
3
SDIO_CMD
4
+3.3V_RUN
5
SDIO_CLK
6
GND
7
SDIO_DAT0
8
SDIO_DAT1
CardDetect
SD_CD#
