W5300 datasheet(100/128 Pages) WIZNET

100 / 128 page

100



ESTABLISHED : Disconnect ? / Disconnecting Process

The connection SOCKET should be disconnected when no more data communication is

required, or FIN packet is received.

{

/* set DISCON command */

Sn_CR = DISCON;

}



ESTABLISHED : CLOSED ?

It checks if SOCKETn is disconnected or closed by DISCON or CLOSE command.

First method :

{

f (Sn_IR(DISCON) == ‘1’) goto CLOSED stage;

/* In this case, if the interrupt of SOCKETn is activated, interrupt occurs. Refer to IR, IMR

Sn_IMR and Sn_IR. */

}

Second method :

{

if (Sn_SSR == SOCK_CLOSED) goto CLOSED stage;

}



ESTABLISHED : Timeout

Timeout can occur when transmitting the TCP packet such as connect-request(SYN

packet) or its response packet(SYN/ACK packet), data(DATA packet) or its response

packet(DATA/ACK packet), disconnect-request(FIN packet) or its response packet(FIN/

ACK packet). If above packets are not transmitted during timeout value set in RTR and

RCR, TCP Final Timeout(TCPTO) occurs and Sn_SSR is changed to SOCK_CLOSED.

TCPTO can be checked as below.

First method :

{

f (Sn_IR(TIMEOUT bit) == ‘1’) Sn_IR(TIMEOUT)=‘1’; goto CLOSED stage;

/* In this case, if the interrupt of SOCKETn is activated, interrupt occurs. Refer to IR, IMR

Sn_IMR and Sn_IR. */

}

Second method :

{

if (Sn_SSR == SOCK_CLOSED) goto CLOSED stage;

W5300 Datasheet(PDF) 100 Page - WIZnet Co., Ltd