W6100 datasheet(91/149 Pages) WIZNET

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W6100 – Hardwired Dual TCP/IP Stack Controller

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}

 Disconnected (Active Close)

This is the active close process.

It transmits the FIN packet to peer.

{

Sn_CR[DISCON] = ‘1’;

/* send FIN Packet */

while(Sn_CR != 0x00);

/* wait until DISCON Command is cleared */

goto Disconnecting Process;

}

 Disconnecting Process

In passive close, if SOCKET n receives FIN packet from peer and it doesn’t have data to

transmit anymore, it transmits FIN packet and closes.

In active close, SOCKET transmits FIN packet to peer and waits for FIN packet from peer. It

closes when it receives FIN packet from peer. If there is no response to FIN packet within the

whole retransmission time, Sn_IR[TIMEOUT] interrupt occurs.

Passive Close: /* received FIN Packet from Destination */

{

Sn_CR = DISCON;

/* send FIN Packet */

while(Sn_CR != 0x00);

/* wait until DISCON Command is cleared */

/* wait unit ACK Packet is received */

while(Sn_IR[DISCON] == ‘0’ and Sn_IR[TIMEOUT] == ‘0’) ;

if (Sn_IR[DISCON] == ‘1’)

{

Sn_IRCLR[DISCON] = ‘1’;

/* clear Interrupt */

goto CLOSED;

}

else goto Timeout?;

}

Active Close : /* sent FIN Packet to Destination */

{

/* wait until FIN Packet is received */

while(Sn_IR[DISCON] == ‘0’ and Sn_IR[TIMEOUT] == ‘0’);

if (Sn_IR[DISOCN] == ‘1’)

W6100 Datasheet(PDF) 91 Page - WIZnet Co., Ltd