Phytec phyCORE-i.MX31, Hardware Manual

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The phyCORE-i.MX on the Development Board
13.5.3.1 UART1 (P1B)
UART1 provides a full set of handshake signals at RS-232 compatible levels. Figure 19 below shows the
signal mapping of the RS-232 level signals to connector P1B.
1 – DCD_DCE1
6 – DSR_DCE1
2 – TXD_DCE1
7 – RTS_DCE1
3 – RXD_DCE1
8 – CTS_DCE1
4 – DTR_DCE1
9 – RI_DCE1
5 - GND
Figure 19: UART1 connector P1B signal description
Two jumpers are provided for additional configuration control of UART1. A detailed description of the
jumpers is provided below, followed by a summary table of the configuration options.
JP1
Controls enabling and disabling the UART1 RS-232 transceivers U1 and U2. By default
this jumper is in the open position, enabling the RS-232 transceivers. Alternatively this
jumper can be set to the closed position, disabling the RS-232 transceivers.
Disabling the UART1 RS-232 transceivers can be useful for connecting your own RS-232
transceiver to the TTL level signals available at the GPIO expansion connector.
JP2
Controls enabling and disabling the UART1 RS-232 transceivers’ auto shutdown feature.
When auto shutdown is enabled the transceivers go into a low power shutdown mode,
consuming minimal power. The transceiver resumes normal operation when signal
activity is detected. By default this jumper is in the open position, enabling auto shutdown.
Alternatively this jumper can be set to the closed position, disabling the auto shutdown
feature and keeping the RS-232 transceivers in their normal operational state at all times.
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PHYTEC Messtechnik GmbH 2007 L-700e_0
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