Thursday, November 26, 2009

Hybrid Mode

What is Hybrid Mode? Hybrid mode is used when both hardware and software TCP/IP processing are required. So what is the advantage of using this kind of system? As you may know, for the hardware TCP/IP stacks, there is a limited number of sockets available. If the user wants to use more sockets than our chip can provide, he can take advantage of the Hybrid mode because the software TCP/IP stack offers unlimited sockets. With the hybrid mode, the user can create unlimited number of sockets since hardware and software TCP/IP stack are running at the same time. In order to use the hybrid mode, MAC raw mode should be setup for the hardware socket 0. The socket 0 will be used as a tunnel to send and receive Ethernet frame for the software stack. While socket 0 is used for the tunneling, the remaining sockets can be used with the hardware stack. Notice that using this hybrid mode, the user is required to port the software stack into the MCU.

I hope you enjoyed. Thank you!

Monday, November 9, 2009

WIZnet Chipset Modes

In this entry, I will explain about the different modes within our chip set. This concept might be hard to understand without a reference model to refer to. That is why I show you this picture
the Bottom Network layers.


Our chipset offers 3 different modes: TCP/UDP Mode, IP Raw Mode, and MAC Raw Mode. Each of these modes represents the different network layer. In MAC RAW mode, the entire Ethernet frame is provided to the MCU without any processing. In IP Raw Mode, the IP datagram is extracted from the Ethernet Frame. In this case, the IP datagram along with the IP header is provided to the MCU. Lastly, in TCP/UDP mode, all the networking headers are removed. You might have expected that TCP/UDP headers are included in the TCP/UDP mode, but actually only the encapsulated data within TCP packets /UDP datagram are provided to the MCU. Most applications use the TCP/UDP mode.

That's it for today. I hope you enjoyed it! Thanks! :)