W3100A Datasheet, PDF (25/63 Pages) List of Unclassifed Manufacturers – i2Chip W3100A

Description of Functions
1. Initialization of W3100A
In order to use W3100A, the basic registers that are required to run W3100A need to be set up. The basic
registers include GAR (Gateway Address Register), SMR (Subnet Mask Register), SHAR (Source Hardware
Address Register), and SIPR (Source IP Address Register).
GAR, SMR and SIPR are the network information on which W3100A is operated, and the registers need to
be set according to the operating environment. SHAR is the Hardware address to be used at the MAC layer
of W3100A, and the address already provided to the manufacturer is used.
After appropriately setting up above registers, W3100A can activate in the network by executing the sys_init
command. Activation can be verified by using Ping (ICMP Echo request).
2. TCP Protocol
TCP is a connection-oriented protocol. By using three-way handshaking method in executing the
connection set-up and termination process, reliable data transmission and reception are assured.
TCP Initialization Process
In order to use W3100A TCP, the protocol field of the corresponding channel’s Cx_SOPR (Socket
Option/Protocol Register of Channel x) needs to be set up as SOCK_STREAM(0x01). After the channel is
activated by sock_init command, Cx_TW_PR (Tx Write Pointer Register of Channel x), Cx_TR_PR (Tx
Read Pointer Register of Channel x), and Cx_TA_PR (Tx Ack Pointer Register of Channel x) need to be
initialized with same value.
TCP Connection Set-up Process
In W3100A, the TCP connection process as directed by Connect or Listen command is processed internally.
Sending SYN Packet as directed by Connect command is called active open, and standing by for SYN Packet
from peer as directed by Listen command is called passive open.
Active open.
TCP Client mode that knows the IP address and port number of the destination, and the connection set-up is
made ahead.
oˆ™‹ž™Œ‹Gp•›Œ™•Œ›Gj–••ŒŠ›› G~¡ˆ™‹GO~p•Œ›SGp•ŠUPG
Y\