Phytec phyCORE-i.MX35, Hardware Manual

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phyCORE-i.MX35
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PHYTEC Messtechnik GmbH 2010 L-734e_1
8 RS-232
8.1 RS232 Transceiver (U12)
One high-speed RS-232 transceiver supporting 460kbps data rates populates the
phyCORE-i.MX35 at U12. This device converts the signal levels for:

RXD/TXD/RTS/CTS (UART2)
The RS-232 interface enables connection of the module to a COM port on a host-PC. In this
instance the RxD line of the transceiver is connected to the TxD line of the COM port; while the
TxD line of the transceiver is connected to the RxD line of the COM port. The ground potential
of the phyCORE-i.MX35 circuitry needs to be connected to the applicable ground pin on the
COM port as well.
The phyCORE-i.MX35 does not convert the remaining available UART (UART1) provided by
the i.MX35x MCU to RS-232 levels. The TTL level signals are made available at the
phyCORE-connector X1 (
see Table 1 ). External RS-232 transceivers must be supplied by the
user if the additional UART requires RS-232 levels.
The maximum baud rate of UART2 is limited to 460,800 bps when used with the on-board
MAX3380 RS-232 transceiver.