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3.3.13 Serial ports
®
With release 2.0 of Qseven
specifications, it has been introduced the possibility of having a serial port directly on Qseven
This interface (eventually managed by the processor/chipset of the Qseven
connection of common PCs or consumer peripherals.
For this reason, on CQ7-A42 carrier board has been introduced a multistandard transceiver, which allows using the serial port interface offered by the Qseven
module in RS-232, RS-422 or RS-485 mode.
JP7 position JP8 position Serial Port #0 working
Not Inserted
Not Inserted
RS-485 Half Duplex mode
Not Inserted
Inserted
RS-485 Full Duplex mode (RS-422)
Inserted
Not relevant
RS-232 mode
According to the working mode selected via jumpers JP7 and JP8, the pinout of the connector will be as described in the following table.
Serial port #0 connector - CN29
Signal RS-485 Full
Pin
Signal RS-232 mode
Duplex mode
1
N.C.
N.C.
2
RxD_0
RX+
3
TxD_0
TX-
4
N.C.
N.C.
5
GND
GND
6
N.C.
N.C.
7
RTS_0#
TX+
8
CTS_0#
RX-
9
N.C.
N.C.
CQ7-A42
CQ7-A42 - Rev. First Edition: 1.0 - Last Edition: 2.0 - Author: S.B. - Reviewed by G.G. Copyright © 2016 SECO S.r.l.
®
module used), is at TTL electrical level, i.e. it cannot be used directly for the
Selection of working mode is made using jumpers JP7 and JP8, which are standard pin
headers, P2.54mm, 1x2 pin.
Please refer to the table on the left for the selection of working mode of the serial port coming
®
out from Qseven
connector.
Such a serial port is available on connector CN29, which is a standard DB-9 male connector.
Please consider that RS-232 signals RxD_0, TxD_0,
Signal RS-485 Half
RTS_0# and CTS_0# are obtained from signals
Duplex mode
UART0_RX, UART0_TX, UART0_RTS# and UART0_CTS# coming out
from Qseven
N.C.
If the Qseven
---
pins, then serial port #0 on connector CN29 will not be usable, neither in
RX-/TX-
RS-232 nor in RS-485 (Half and Full Duplex) modes.
N.C.
GND
N.C.
RX+/TX+
---
N.C.
®
card edge connector.
®
card edge connector.
®
module used doesn't support the UART interface in those
®
40
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