AN2692 Freescale Semiconductor / Motorola, AN2692 Datasheet - Page 4

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

Introduction
Ethernet is not the only component of the communication mechanism required for LAN operation.
Figure 3
that uses LAN. The network interface block is where Ethernet is positioned in the LAN communication
model.
which in turn is derived from ISO’s (the International Organization for Standardization) OSI (open systems
interface model) 7-layer theoretical communications model.
The functionality that the data link layer and the physical layer provides to the LAN communication model
is very important. These layers work together to provide access to the analog world of the UTP cable. The
following bullets list some of the basic functions performed by the data link layer and the physical layer.
This document will provide a brief overview of TCP/IP stack software, but TCP/IP stack software is not
the focus of this document.
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Encapsulated data portion — 46 to 1500 bytes of user data.
Frame check sequence trailer (frame check sequence) — 4-byte value that contains a 32-bit cyclic
redundancy check (CRC) value.
Data link layer — MAC
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Physical layer — PHY
–
Figure 3
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6
5
4
3
2
1
provides a more complete look at the communication model used by a generic user application
Packet error checking
Data framing
Network access
Analog signaling
ISO’S OSI MODEL
PRESENTATION
APPLICATION
TRANSPORT
NETWORK
NETWORK
DATA LINK
shows that the simplified block version provided is actually derived from a TCP/IP model,
SESSION
PHYSICAL
Figure 3. Block Diagram of TCP/IP Stack Model
MC9S12NE64 Integrated Ethernet Controller, Rev. 0.2
TCP/IP MODEL
APPLICATION
TRANSPORT
NETWORK
LINK
NETWORK INTERFACE
USER APPLICATION
HTTP, TFTP, SMTP,
DHCP, SNMP, etc...
IP, ARP, ICMP
TCP, UDP
AND PHYSICAL INTERFACE
ETHERNET CONTROLLER
SOCKET API
TCP STACK
SOFTWARE
APPLICATION API
Freescale Semiconductor
DEVICE DRIVER API