Phytec phyCORE-i.MX35, Hardware Manual

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RS-232

PHYTEC Messtechnik GmbH 2010 L-734e_1
39
8.1.1 UART2 Routing (RN4)
RN4 is used to route the signals of UART2 serial interface through the RS-232 transceiver or
around the RS-232 transceiver when populated. When RN4 is not populated
UART2_RXD_TTL, UART2_TXD_TTL, UART2_RTS_TTL and UART2_CTS_TTL are routed
through the RS-232 transceiver U12 and come out as X_UART2_RXD, X_UART2_TXD,
x_UART2_RTS and x_UART2_CTS at the phyCORE-connector pins X1 pin 22D, X1 pin 23D,
X1 pin 25D, X1 pin 26D. If U12 does not populate the module, RN4 is populated to route the
TTL level signals to these same pins.
The standard phyCORE-i.MX35 module will have U12 populated, thereby routing the RS-232
level signals to the phyCORE-connector. Be sure the phyCORE-i.MX35 configuration you are
working with before interfacing these signals outside of the module as incorrect voltage levels
will likely cause damage to on-board and off-board components.
The following configurations are possible:
Table 11: RN4 UART2 Signal Routing
1
S
IGNAL
C
ONFIGURATION
RN4
X_UART2_RXD, X_UART2_TXD, X_UART2_ RTS, X_
UART2_CTS as RS-232 level signals at X1 pin 22D, X1 pin
23D, X1 pin 25D and X1 pin 26D not populated
X_UART2_RXD, X_UART2_TXD, X_UART2_ RTS, X_
UART2_CTS as TTL level signals at X1 pin 22D, X1 pin
23D, X1 pin 25D and X1 pin 26D populated
1 : Defaults are in
bold blue text