AN2836 Freescale Semiconductor / Motorola, AN2836 Datasheet - Page 9

• Manufacturer Part Number: AN2836
• Description: Web Server Development with MC9S12NE64 and OpenTCP
• Manufacturer: Freescale Semiconductor / Motorola

OpenTCP TCP/IP Stack Overview
This section includes:
OpenTCP Introduction
OpenTCP is a robust and portable implementation of the TCP/IP and Internet application-layer protocols.
Originally developed by Viola Systems (http://www.violasystems.com/index.php), OpenTCP was
released under an Open Source license. It includes protocols such as ARP, IPv4, ICMP, UDP, TCP,
HTTP, BOOTP, TFTP, POP3, and SMTP. A port of OpenTCP is provided for the MC9S12NE64 at
SourceForge (the direct web address is http://freescaleotcp.sourceforge.net/). SourceForge is the world’s
largest repository of Open Source code, providing a forum for MC9S12NE64 OpenTCP developers to
provide enhancements and resolve issues.
OpenTCP is a CodeWarrior compatible TCP/IP stack implementation that is tailored for 8-bit and 16-bit
embedded processors. To reduce the OpenTCP code footprint in FLASH, ROM, and RAM, OpenTCP has
made several TCP/IP stack design choices that deviate from TCP/IP’s RFC standards while still
maintaining high TCP/IP stack functionality and interoperability. These include:
Freescale Semiconductor Low-Level Ethernet Drivers
Powering the OpenTCP TCP/IP stack is a low-level Ethernet driver for the MC9S12NE64 integrated
Ethernet controller. This driver is integrated within the OpenTCP TCP/IP stack source code. However, a
Freescale stand-alone (without a TCP/IP stack) version of the low-level Ethernet driver is available for
stand-alone development.
OpenTCP Project Installation and Organization
The OpenTCP source code is provided in a zip file. When the OpenTCP zip file is extracted, several
directories are placed on the target PC.
Freescale Semiconductor
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OpenTCP introduction
Freescale Semiconductor low-level Ethernet drivers
OpenTCP installation and project organization
OpenTCP CodeWarrior project
OpenTCP TCP/IP stack API
No support for IEEE 802.3 type packets
No IP option support
No support to handle fragmented packets
ICMP supports only echo reply
Ignores all TCP options
Every TCP packet must be acknowledged with an ACK before another one can be received
Web Server Development with MC9S12NE64 and OpenTCP, Rev. 0
Figure 7
illustrates the OpenTCP project directories.
OpenTCP TCP/IP Stack Overview
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