CCOMe-965
CCOMe-965 - Rev. First Edition: 1.0 - Last Edition: 3.0 - Author: S.B. - Reviewed by G.G. Copyright © 2016 SECO S.r.l.
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3.3.24
UART + GPIO/SD Pin Header
With release 2.0 of COM Express specifications, it has been introduced the possibility
of having two serial ports directly on COM Express connector A-B.
This interface (eventually managed by the processor/chipset of the COM Express
module used), is at TTL electrical level, i.e. it cannot be used directly for the connection of
common PCs or consumer peripherals.
For this reason, on CCOMe-965 carrier board has been introduced a dedicated
transceiver, which allows using the serial port interface offered by the COM Express
module in RS-232 mode.
Moreover, with Release 2.0 of COM Express specifications, the four General Purpose
Inputs and the four general Purpose Outputs have been redefined, so that they can also
be used for SDIO implementation. 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.
All these interfaces are available on CN27, which is a dual row, 16 pin, P2.54mm standard pin header, with the pinout shown in the table
on the left.
Please consider that RS-232 signals 232_SER0_RX, 232_SER0_TX, 232_SER1_RX and 232_SER1_TX are obtained, via the RS-232 transceiver, from signals
SER0_RX, SER0_TX, SER1_RX and SER1_TX coming out from COM Express connector CN1.
Signals description
SD_CD#: Card Detect Input.
SD_CLK: SD Clock Line (output).
SD_CMD: Command/Response bidirectional line.
SD_WP: SD Write Protect Input 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.
UART + GPIO/SD pin header - CN27
Pin Signal
Pin Signal
1
232_SER0_RX
2
232_SER1_RX
3
232_SER0_TX
4
232_SER1_TX
5
GND
6
GND
7
GPI0/SD_DATA0
8
GPI1/SD_DATA1
9
GPI2/SD_DATA2
10
GPI3/SD_DATA3
11
GPO0/SD_CLK
12
GPO1/SD_CMD
13
GPO2/SD_WP
14
GPO3/SD_CD#
15
+3.3V_S
16
GND
