AN2692 Freescale Semiconductor / Motorola, AN2692 Datasheet - Page 36

• Manufacturer Part Number: AN2692
• Description: MC9S12NE64 Integrated Ethernet Controller
• Manufacturer: Freescale Semiconductor / Motorola

Network Data Transaction at Upper Layer Protocols
Network Data Transaction at Upper Layer Protocols
Reception and transmission of Ethernet packets as described in the
Interface
such as TCP/IP is used to initiate and maintain communications within the network and assist the user
network application.
how the user data from the user application is encapsulated and eventually is transmitted.
When a packet is received, the protocol layers are decoded and removed. This process, called de-
encapsulation, correctly processes the packet with the appropriate upper layer protocols to access the
user data.
Table 4
are components of a TCP/IP stack. Transmission and reception of user data at the upper protocol layers
is managed by TCP/IP software. A TCP/IP stack defines a set of protocols that allows network devices to
connect to a specific device and exchange data on a network. These protocols, defined by RFC (request
for comments), enable an embedded device to send email, serve web pages, transfer files, and provide
other basic connectivity functions.
36
describes some of the upper layer protocols shown in
section is not the level that typical user Ethernet applications use. Typically, a software stack
Figure 27. User Data Encapsulated to and from the Upper Layers TCP/IP Model
ETHERNET
HEADER
14
Figure 3
HEADER
IP
20
MC9S12NE64 Integrated Ethernet Controller, Rev. 0.2
shows ISO’s OSI communication model.
HEADER
HEADER
ETHERNET FRAME
TCP
TCP
20
46 to 1500 BYTE
IP DATAGRAM
TCP SEGMENT
APPLICATION
HEADER
APPLICATION DATA
APPLICATION DATA
APPLICATION DATA
USER DATA
USER DATA
Figure 3
Using the MC9S12NE64 Ethernet
ETHERNET
Figure 27
TRAILER
and
4
Figure
provides an overview of
27. These protocols
Freescale Semiconductor
APPLICATION
INTERFACE
ETHERNET
NETWORK
TCP
IP