The various data acquisition components of the microcontroller are used to provide data to the microcontroller for processing.

The microcontroller will receive packets from the Ethernet Transceiver. It will then process these packets, and if needed, retrieve data from the I/O. Then it will respond by sending a packet to the Ethernet Transceiver.

When a user on the other side of the Ethernet Network contacts the microcontroller, the Ethernet Transceiver receives a packet from the network. It then processes this packet and transfers it to the microcontroller. When the microcontroller is done p rocessing the packet, it transfers a response packet to the Ethernet Transceiver, which then passes the packet back to the Ethernet Network. The purpose of the Ethernet Transceiver is to translate packets of data into voltage levels for transmission.

The software for the microcontroller will be composed of three main parts, as shown in the flow chart in Figure 2. The first is a loop that checks if a packet is waiting in the Ethernet Transceiver, and if there is a packet there it will retrieve it. The next part will decode the packet and transfer the pertinent information to the appropriate packet processing function. These functions are the last part, and they process each type of packet and send the appropriate response. Table 2 shows the packet type, it’s function, and the response. TCP is the protocol used by the user’s web browser to retrieve information from the web server in the microcontroller. Since not all of the functions supported by TCP will be needed for this design, only a s ubset of the full TCP protocol will be implemented.