Specifications

SLAA137A
MSP430 Internet Connectivity 13
Init8900()
User Program
Write8900(ADD_PORT, PP_RxEvent)
(Read8900(DATA_PORT)
& RX_OK)?
CopyFromFrame8900(...)
Application Wants
to Send Data?
RequestSend(FrameSize)
Rdy4Tx()?
RequestSend(FrameSize)
Yes
No
No
Yes
Yes
No
Figure 5. Using the Ethernet Module
4.2 TCP/IP Module
This software module represents the most important part of the demonstration board because
the protocols for transferring data over a TCP/IP connection are implemented here. It uses
functions of the ethernet module to send and receive data and provides a simple, easy-to-use
API to the upper application layer.
Basically the module tcpip.c is a collection of event-handling procedures and some help
functions (for example, reversing the byte order of words). In a TCP/IP stack one of the following
events can occur:
• A frame is received over the LAN
• The application triggers an event (for example opens a connection, sends data…)