22
6 F 3 B 0 3 6 2
1.5 Software Organization
The Ethernet Port transmission functions (computer link protocol transmission, PC link protocol
transmission and socket interface transmission) are implemented with the software organization
shown in the figure.
T2N user program
T2N firmware
Computer link/PC link/socket interface
Ethernet Port interface
UDP TCP
IP ARP ICMP
CSMA/CD
10BASE-T
Figure 1.7 Software Organization
TCP (transmission control protocol)
Before transferring data with the remote port, a connection (virtual communication circuit) is first
established and then data is transferred. Transmission reliability is guaranteed by packet order
control, retransmission, flow control, and other techniques.
The Ethernet Port supports the following:
•Response bit (ACK)
•Push bit (PSH)
•Synchronized bit (SYN)
•Fin bit (FIN)
•Retransferring
•Window (flow) control
•Segment division
•Reporting of the maximum receivable segment length
The Ethernet Port does not support the reset bit (RST).
SEND/RECV instruction
T2N internal bus
T2N Upper Protocol
software
Ethernet
Port