Functional Descriptions

By setting some register and memory operation, W5100 provides internet connectivity. This
chapter describes how it can be operated.

Initialization

Basic Setting
For the W5100 operation, select and utilize appropriate registers shown below.
1. Mode Register (MR)
2. Interrupt Mask Register (IMR)
3. Retry Time-value Register (RTR)
4. Retry Count Register (RCR)
For more information of above registers, refer to the “Register Descriptions”.

Setting network information
Below register is for basic network configuration information to be configured according to
the network environment.
1. Gateway Address Register (GAR)
2. Source Hardware Address Register (SHAR)
3. Subnet Mask Register (SUBR)
4. Source IP Address Register (SIPR)
The Source Hardware Address Register (SHAR) is the H/W address to be used in MAC layer, and
can be used with the address that manufacturer has been assigned. The MAC address can be
assigned from IEEE. For more detail, refer to IEEE homepage.

Set socket memory information
This stage sets the socket tx/rx memory information. The base address and mask address of
each socket are fixed and saved in this stage.

UNDER EDITING

Data Communications
Data communication is available through TCP, UDP, IP-Raw and MAC-Raw . In order to select it,configure protocol field of Socket n Mode Register(Sn_MR) of the communication sockets
(W5100 supports total 4 sockets).

TCP
TCP is the connection based communication method that will establish connection in advance
and deliver the data through the connection by using IP Address and Port number of the
systems. There are two methods to establish the connection. One is SERVER mode(passive
open) that is waiting for connection request. The other is CLIENT mode (active open) that
sends connection request to a server.