2:Description and Specifications
XPort Direct™ Integration Guide/Data Sheet
9
PCB Interface
The XPort Direct has a serial port compatible with data rates up to 230 Kbaud. The
serial interface pins i3.3V, ground, and reset. The serial signals usually
connect to an internal device, such as the UART port of the host device's
microcontroller. For applications requiring an external cable running with RS-232 or
RS422/485 voltage levels, the XPort Direct must interface to a serial transceiver chip.
Table 2-1. PCB Interface Signals
Signal Name
Direct
Pin #
Primary Function
GND 1,2
Circuit
ground
3.3V
3
+3.3V power in
Reset#
5
External reset in
Data Out
7
Serial data out (driven by DSTni’s built-in UART)
Data In
9
Serial data in (read by DSTni’s built-in UART)
RTS 11
Flow control out: RTS (Request to Send) output driven
by DSTni’s built-in UART for connection to CTS of
attached device. RTS is used as transmit enable in
RS485 mode.
DTR
13
Modem control: DTR (Data Terminal Ready) output
driven by DSTni’s built-in UART for connection to DCD
of attached device.
CTS
15
Flow control in: CTS (Clear to Send) input read by
DSTni’s built-in UART for connection to RTS of
attached device.
I2CCLK
17
Reserved
I2C DATA
19
Reserved
CP2
21
General Purpose IO pin
CP1
23
General Purpose IO Pin
Chassis
24
Chassis Ground Pin
NC
10,22
No Connect Pins
Reserved
4,6,8,12,
14,16,18,
20
Reserved Pins, Do not connect
The Ethernet interface magnetics, RJ45 connector, and Ethernet status LEDs are all
integrated in the XPort Direct.
Note:
For RS232 connections, see Demo Board Schematic on page 13. For
RS485 connections, see Figure 2-3 below.
