Digilent PmodRS232X - Manual

P P m m o o d d R R S S 2 2 3 3 2 2 X X ™ ™
R R e e f f e e r r e e n n c c e e M M a a n n u u a a l l
Revision: July 30, 2012
Note: This document applies to REV A of the board.
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Analog
Devices
ADM3232E
RS232
Transceiver
DC
E
Co
n
n
e
c
to
r
DB
9
Pins 1,4,6 are tied
for handshaking.
NC
1
6
4
9
8
3
7
2
5
J1
1
2
3
4
5
6
CTS
RTS
TXD
RXD
JP1 JP2
GND
VCC
RS232 Module Block Diagram
Overview
The PmodRS232X Converter Module
translates voltage from the logic levels used by
Digilent system boards to the RS232 voltage
used for serial communications.
The PmodRS232X creates a two-way I/O
exchange by converting RS232 voltage to
logic-level voltage and converting logic voltage
to RS232 voltage. RS232 voltage levels are -3
to -12V for a logic ‘1’, and +3 to +12 for a logic
‘0’.
The PmodRS232X is configured as a data
communications equipment (DCE) device. It
connects to data terminal equipment (DTE)
devices, such as the serial port on a PC, using
a straight-through cable.
Features include:
•
an Analog Devices ADM3232ERS232
transceiver
•
a DB9 connector and 6-pin header
•
transmit and receive data functions
•
optional RTS and CTS handshaking
functions
•
small form factor (1.00” x 1.30”)
Functional Description
The RS232 module provides two transmit
buffers and two receive buffers. A transmit
buffer converts a logic-level signal on its input
to an RS232 voltage-level signal on its output.
A receive buffer converts an RS232 voltage-
level signal on its input to a logic-level signal
on its output.
The RS232 module can be configured as
either a 3-wire DTE serial port (with one
transmitter for transmit-data signals, one
receiver for receive-data signals, and a signal-
ground connection), or as a 5-wire DTE serial
port with an additional transmitter and receiver
for RTS and CTS handshaking signals,
respectively.
The PmodRS232X is designed to work with
either Digilent programmable logic system
boards or embedded control boards. Most
Digilent system boards (like the Basys, Nexys,
or Cerebot) have 6-pin connectors that allow
the PmodRS232X to plug directly into the
system board or to connect via a Digilent 6-pin
cable.