Ethernet Module

Introduction

• This project aims to develop an Ethernet Module, to be used in conjunction with a 8/16 bits embedded system such as the dsPic33F development board.
• The entire Ethernet Module consists of:

1. Hardware: a LAN card based on Davicom DM9000A chip
2. Software: a TCP/IP stack based on uIP 1.0

Useful Links

DM9000A

• DM9000A Description
• DM9000A Datasheet
• Application Circuit
• Layout Guidelines
• Application Note
• DM9000A Official Drivers

uIP

• uIP Description
• uIP Documentation
• Download
• CVS Repository

lwIP

• lwIP Description
• Documentation

HTML

• W3 Schools: Learning how to write HTML and JavaScript
• Nvu: Open source HTML Editor

SNMP

• SNMP Link: Information on SNMP Agents
• IANA: Applying a Private Enterprise Number

Hardware

Component List

Special Item	Description	Quantity
DM9000AEP	Ethernet Controller	1
HR911102A	RJ45 Connector with Integrated Magnetics for 10/100 Base-TX	1
93LC46B-I/SN	1K Serial EEPROM	1 (Optional)
25MHz Crystal	Crystal	1
22pF	For Crystal Use	2
220uF	For RXVDD25/TXVDD25	1
49.9ohm	For RX+/RX-/TX+/TX-	4
6.8kohm	For BGRES/BGGND	1
510ohm	For LEDs	2

Circuit and PCB

in gEDA format and its gEDA sym and footprints

Software Driver

• Download here
• Base on FreeRTOS and dsPIC33 platform
• Using POSIX-like API:
  • int dmfe_open(int flags): initialize the Ethernet controller for 10MHz Half-Duplex
  • int dmfe_close(): turn off the PHY layer
  • int dmfe_read(void): copy a packet to the default buffer
  • int dmfe_write(unsigned char device, unsigned char *buf, int count): copy count bytes of the data from buf and transmit
  • void dmfe_interrupt(void): process the transmit interrupt from DM9000A

TCP/IP Stack

• uIP and lwIP are light weight TCP/IP Stack designed for 8-bit/16-bit embedded systems.

uIP

• Develped by Adam Dunkels of the Networked Embedded Systems group at the Swedish Institute of Computer Science.
• uIP is under the BSD-style license

lwIP

• lwIP is a small independent implementation of uIP.
• It is more powerful than uIP but requires more memory.
• lwIP is under the Modified BSD License

Ethernet Application

DHCP Client

• To be added.

Web Server

• To be added.

SNMP Agent

• Simple Network Management Protocol (SNMP) is a standard protocol to access variables to remote device via the Internet.
• It belongs to the Application Layer, as in HTTP.
• If a device is SNMP compatible, any SNMP compatible host system can monitor and control that device.

Components in a SNMP System

• Network Management Station (NMS)
  • This is a client, initiating SNMP communication.
  • This can be a PC with an NMS software, polling data from the SNMP agents periodically.
• SNMP Agents
  • These are servers, responding to one or multiple NMS requests.
• Management Information Base (MIB)
  • A special collection of variables managed by the SNMP agents.
  • MIB has a tree-like structure.
  • An Object Identifier (OID) is given for each node.
  • Data are stored at the end-nodes.
  • Private variables may be constructed under the "enterprise" sub-tree.
  • The OID (41.6.1.4.X) for "enterprise" can be obtained from Internet Assigned Number Authority (IANA).