Theory of operation

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Figure 2.

IAP using Ethernet

The full TCP/IP suite consists of numerous protocols, ranging from the low level protocol to

the application level protocol.

The TCP/IP suite uses encapsulation to provide abstraction of protocols and services.

Generally, a protocol at a higher level uses a protocol at a lower level to help it fulfil its

purpose.

Figure 3.

Example of TCP/IP encapsulation

The control of the physical layer is performed by the ENET FWLib, which is the Ethernet

driver developed by STMicroelectronics for the STR91xFA MAC/DMA controller (ENET). For

more information please refer to STR91xFA ENET Firmware Library User Manual

(UM0248).

1.2.3

Application layer

The Application Layer is in charge of loading the file. The TCP/IP stack provides dedicated

solutions for file loading over network, such as the Trivial File Transfer Protocol (TFTP)

which is a very simple file transfer protocol.

This protocol transfers files from a server following a request. Therefore, you must have

TFTP server on the network to perform file loading.

Binary file of

the new

firmware

STR912F board

PC

TCP/IP

Application Data

TCP/UDP

header

IP header

Ethernet

header

Application Data

TCP Segment

IP Datagram

Physical

Encapsulation

Ethernet frame

FCS