W5200 datasheet(68/88 Pages) WIZNET

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SOCKET Initialization

Select the SOCKET and set the SN_MR(P3:P0) to MACRAW mode. Then execute the ‘OPEN’

command. After the ‘OPEN’ command, if the Sn_SR is successfully changed to

‘SOCK_MACRAW’, the SOCKET initialization is completed. Since all information about

communication (Source hardware address, Source IP address, Source port number,

Destination hardware address, Destination IP address, Destination port number, Protocol

header, etc.) is in the ‘MACRAW data’, there is no more register setting.

{

START:

/* sets MAC raw mode */

S0_MR = 0x04;

/* sets OPEN command */

S0_CR = OPEN;

/* wait until Sn_SR is changed to SOCK_MACRAW */

if (Sn_SR != SOCK_MACRAW) S0_CR = CLOSE; goto START;

}

Check received data

Refer to the “5.2.2.1 Unicast & Broadcast.”

Receiving process

Process the MACRAW data of the SOCKET which received it in internal RX memory.

The structure of the MACRAW data is as below:

Figure 17 The received MACRAW data Format

The MACRAW data consists of ‘PACKET-INFO,’ ‘DATA packet’ and 4bytes CRC. The ‘PACKET-

INFO’ is the length of the DATA packet. The ‘DATA packet’ consists of 6bytes ‘Destination

MAC address,’ 6bytes ‘Source MAC address’ and 2bytes ‘Type,’ 46~1500 bytes ‘Payload.’

The ‘Payload’ of DATA packet consists of Internet protocol such as ARP, IP according to the

‘Type.’ The details of ‘Type’ please refer to the web:

(

http://www.iana.org/assignments/ethernet-numbers

)

{

/* calculate offset address */

src_mask = Sn_RX_RD & gSn_RX_MASK;

// src_mask is offset address

/* calculate start address(physical address) */

W5200 Datasheet(PDF) 68 Page - WIZnet Co., Ltd