Eurotech An0038 Installation and operating instructions

EmbeddedDNA
®
PC/104 CPU Module
CPU-1220; Ethernet Aapter
Rev. 1.0 Apr 2004
COPYRIGHT 1994-2005 Eurotech S.p.A. All Rights Reserved.
An003
8

2 Application Note
ABOUT THIS MANUAL
This application note is intended to help users detecting which Ethernet interface is installed over the CPU-1220.
Via J. Linussio 1
33020 AMARO (UD)
ITALY
Phone: [phone]
Fax: [phone]
web: http://www.eurotech.it
e-mail: mailto:[email protected]
NOTICE
Although all the information contained herein has been carefully verified, Eurotech S.p.A. assumes no
responsibility for errors that might appear in this document, or for damage to property or persons
resulting from an improper use of this manual and of the related software. Eurotech S.p.A. reserves the
right to change the contents and form of this document, as well as the features and specifications of its
products at any time, without notice.
Trademarks and registered trademarks appearing in this document are the property of their respective owners

Application Note 3
Conventions
The following table lists conventions used throughout this guide.
Icon Notice Type Description
Information note Important features or
instructions
Warning
Information to alert you to
potential damage to a program,
system or device or potential
personal injury

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Contents
Conventions ................................................................................................................................................... 3
Contents ........................................................................................................................................................... 5
Chapter 1 CPU-1220 Ethernet interface ................................................................................................... 7
Detecting the Realtek chipset version installed into your CPU-1220 ............................................................ 7
Ethernet interface........................................................................................................................................... 8
J4: CPU-1220 Ethernet connector .......................................................................................................... 8
J9: Status LEDs....................................................................................................................................... 9
Ethernet physical adapter .............................................................................................................................. 9
Related Documents ....................................................................................................................................... 13

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Chapter 1 CPU-1220 Ethernet interface
The CPU-1220 Ethernet interface features a single-chip Fast Ethernet controller Realtek RTL8139 that
provides 32-bit performance, 10/100Mbps auto-sensing, and full compliance with IEEE 802.3u 100Base-T
specifications and IEEE 802.3x Full Duplex Flow Control.
The versions of the Relatek RTL8139 chipset installable over the CPU-1220 board are:
- RTL8139 B
- RTL8139 C
Between the two devices there are only different electrical characteristics. It is important to know which
version of RTL8139 is installed on the board to select the proper Ethernet physical adapter and to connect or
to develop custom circuitry.
Detecting the Realtek chipset version installed into your CPU-1220
To detect which version of Realtek chipset is installed on the CPU-1220, read the printed label on the
Realtek RTL8139 chip.
Figure 1. The Realtek RTL8139 chip

8 Application Note
Comparing the CPU-1220 serial number1with the following table is possible to detect the installed chipset
version:
Table 1. CPU-1220 RTL8139 chipset version
CPU-1220 Eurotech s/n Realtek RTL8139 version
Till S.N. 229904389 B
Starting from 03M241 S.N. 229904390 C
Ethernet interface
The CPU-1220 module provides the following interfaces:
 J4 for a 10/100 Ethernet (LAN) connection. J4 is a 5x2 pin – 2.54mm step connector
 J9 for status LEDs: one for the HDD status, three for the Ethernet status. J9 is a 3x2 pin - 2mm step
connector
J4
LED
IDE
Ethernet
Figure 2. J13 IDE Connector layout
J4: CPU-1220 Ethernet connector
The J4 Ethernet connector is a 5x2 pin with 2.54-mm step. Refer to the following table for the Ethernet
connector assignment.
Table 2. J4 Ethernet Connector
Pin# Signal Function
1 +5V or +3,3V2Power Supply
2 LED0 On sending packets
3 RX+ 100/10Base-T receive data
4 RX- 100/10Base-T receive data
5 LED1 Link 10/100
1The Serial number of the CPU-1220 board is a bar code label printed on the PC/104 connector and
consists of a 10 characters length code.
2Depending on the Realtek chipset installed: if Realtek RTL8139B is installed power supply is +5V, if
RTL8139C is installed +3,3V supplied. For detailed electrical information please refer to the chipset
datasheet.

Application Note 9
6 GND Ground signal
7 LED2 On receiving packets
8 GND Ground signal
9 TX+ 100/10Base-T transmit data
10 TX- 100/10Base-T transmit data
J9: Status LEDs
The HDD and Ethernet activity LEDs are implemented on the J9 connector. It is a 3x2 pin - 2mm step.
The following table shows the J9 connector pinout:
Table 3. J9 LED Connector
Pin Signal Function
1 VDD IDE LED anode
2 IDE LED IDE LED cathode
3 5V_LAN LAN LEDs
common anode
4 LAN LED 2 LAN LED cathode
5 LAN LED 0 LAN LED cathode
6 LAN LED 1 LAN LED cathode
The meaning of LAN LEDs is the following:
 LAN LED 0: TX
 LAN LED 1: Link 10/100 (LAN LED 1 signals that the correct connection is established)
 LAN LED 2: RX
Ethernet physical adapter
Note: To establish a connection to the Ethernet, the Eurotech Ethernet Adapter can be plugged
between the CPU board (to the J4 connector) and the net cable.
It is shown below.
RJ45 Connector
To CPU Board
Ethernet
Connector
Figure 3. Eurotech Ethernet Adapter
The green led is fixed, and signals the correct connection of the module.
The yellow led blinks when there is activity (data IN/OUT) on the net connection.
With RJ45 connectors, only twisted pair cables can be used.

10 Application Note
Important Note. Connection to a 100BASE-TX hub for 100 Mbps operation requires Cat. 5
Unshielded Twisted-Pair (UTP) cable or Cat. 5 Shielded Twisted-Pair (STP) cable. The maximum
length between the 100BASE-TX hub and the adapter is 100 meters. Connection to a 10BASE-T hub
for 10 Mbps operation requires a Cat. 3, 4, 5 UTP cable or Cat. 5 STP cable. Preferred maximum
cable length between CPU-1220 module and Ethernet adapter is 10 cm (4”)
Ethernet physical adapter Versions
This physical adapter is available in two different versions:
Table 4. Physical Adapter code
EurotechCODE Description Valid for
RTL8139
ACS-9071-00 RJ45 ETHERNET ADAPTER FOR CPU-1220 AND CPU-1231 B
ACS-9071-03 RJ45 Ethernet adapter for CPU-1232 and CPU-1220 C
Warning: To prevent incorrect data transmissions select the proper physical adapter device
depending on the Realtek RTL8139 chipset installed on the CPU-1220.
Integration of the Ethernet physical adapter
If the Ethernet physical adapter has to be integrated over a custom circuitry, please refer to Eurotech for
detailed information about schematics.
Regarding schematics, a good choice is isolating the Ethernet adapter section from the rest of the power
supply section. Derive the supply directly from the J4 Ethernet Connector of the CPU-1220. In this way if
different versions of Realtek RTL8139 chipsets are installed no damage occurs when you connect J4 to the
carrier board.
Warning: please take care on the Realtek RTL8139 version used in order to avoid short-circuits
between +5V and +3.3V when deriving power supply.

Application Note 11
Generic Ethernet adapter
Eurotech has developed a fail-safe circuitry that can be installed to prevent faulty and damages. To prevent
wrong connections between the CPU-1220 and the Ethernet adapter Eurotech has developed a generic
adapter that can be used together with the CPU-1220 for installing both the Realtek chips.
The following drawing describes the solution for a generic Ethernet adapter tolerant regarding the supply
voltage present on pin 1 of J4 CPU-1220 Ethernet connector and based on the version of the Realtek
RTL8139 chipset installed, and that may be integrated into a carrier board.
Figure 4. Generic Ethernet Adapter Schematics
For detailed information regarding the Ethernet Adapter please contact Eurotech.
Auxiliary
C
ir
cu
i
t
r
y

12 Application Note
Chapter 2 Drivers
Visit the Eurotech web site for the latest driver availability.

Application Note 13
Related Documents
For detailed information on the CPU-1220 board please refer to the User Manual.
For further information about the Realtek RTL8139X please refer to the technical Data Sheet.