Development Kit
XPort™ Integration Guide
15
valid, whether the serial interface transmit data and serial interface receive data are
active, and the state of the three configurable pins, CP1, CP2, and CP3.
The PLD and a six-position DIP switch control the evaluation board mode of
operation. The switch outputs are inputs to the PLD to select the desired mode of
operation.
Evaluation Board Block Diagram
TP8
TP9
XPort
DIP
SWITCH
RESET
+5
VDC
IN
3.3V
POWER
PIO
RS232
PLD
TMR
LEDs
SLOW
PWR
LED
RTS, DCD
DTR, CTS
PLD HEADER
RXD/TXD
SWITCH
RESET
PADS
JP3
JP4
J1
D2
SW1
SW2
DB-9F
TP13
TP11
RTS
DTR
CTS/DCD
Major Components
The major components of the evaluation board include:
RS-232 transceiver
Universal Power Adapter
Reset switch
DIP switch
DB9 interface connector (DCE)
Test points to monitor all XPort pins
6-pin header (JP4) for connecting user devices or circuits to CP1, CP2, and
CP3.
Power, signal ground, and reset inputs are also available on JP4.
Serial RS-232 Interface
The RS-232 level serial interface is implemented with a transceiver that converts
3.3V CMOS levels to RS-232 levels. A straight-through serial cable with 9-pin
connectors (M/F) is all you need to connect to a DTE device such as a PC.
The table below lists the RS-232 signals. Note that XPort signal pins 6, 7, and 8 are
configurable pins you can optionally set for functions other than RS-232 control. The
configuration DIP switch determines whether or not to route the XPort configurable
pins to the RS-232 converter.
Table 3-1. RS-232 Signals
XPort Signal
XPort Pin #
Direction
DB9 Pin #
DTE Device Signal
DTR 7
Out
1
DCD
Data Out
4
Out
2
RXD
Data In
5
In
3
TXD
DCD 8
In
4
DTR
