Pcb Interface; Table 2-1. Pcb Interface Signals - Lantronix XPort Direct Integration Manual

PCB Interface

The XPort Direct has a serial port compatible with data rates up to 230 Kbaud. The
serial interface pins include +3.3V, 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.
Signal Name
GND
3.3V
Reset#
Data Out
Data In
RTS
DTR
CTS
I2CCLK
I2C DATA
CP2
CP1
Chassis
NC
Reserved
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.
XPort Direct™ Integration Guide/Data Sheet

Table 2-1. PCB Interface Signals

Direct Primary Function
Pin #
1,2 Circuit ground
3 +3.3V power in
5 External reset in
7 Serial data out (driven by DSTni's built-in UART)
9 Serial data in (read by DSTni's built-in UART)
Flow control out: RTS (Request to Send) output driven
11
by DSTni's built-in UART for connection to CTS of
attached device. RTS is used as transmit enable in
RS485 mode.
Modem control: DTR (Data Terminal Ready) output
13
driven by DSTni's built-in UART for connection to DCD
of attached device.
Flow control in: CTS (Clear to Send) input read by
15
DSTni's built-in UART for connection to RTS of
attached device.
Reserved
17
Reserved
19
General Purpose IO pin
21
General Purpose IO Pin
23
Chassis Ground Pin
24
No Connect Pins
10,22
Reserved Pins, Do not connect
4,6,8,12,
14,16,18,
20
2:Description and Specifications
9