W5100 datasheet(34/72 Pages) WIZNET

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Sn_PROTO (Socket n IP Protocol Register) [R/W] [0x0414, 0x0514, 0x0614, 0x0714]

[0x00]

This IP Protocol Register is used to set up the Protocol Field of IP Header at the IP Layer RAW

Mode. There are several protocol numbers defined in advance by registering to IANA. For the

overall list of upper level protocol identification number that IP is using, refer to online

documents of IANA (http://www.iana.org/assignments/protocol-numbers).

Ex) Internet Control Message Protocol (ICMP) = 0x01, Internet Group Management Protocol =

0x02

Sn_TOS (Socket n IP Type Of Service Register) [R/W] [0x0415,0x0515,0x0615,0x0715]

[0x00]

This register sets up at the TOS(Type of Service) Field of IP Header.

Sn_TTL (Socket n IP Time To Live Register) [R/W] [0x0416,0x0516,0x0616,0x0716] [0x80]

This register sets up at the TTL(Time To Live) Field of IP Header.

Sn_TX_FSR (Socket n TX Free Size Register) [R] [0x0420-0x0421, 0x0520-0x0521,

0x0620-0x0621, 0x0720-0x0721] [0x0800]

This register notifies the information of data size that user can transmit. For data

transmission, user should check this value first and control the size of transmitting data.

When checking this register, user should read upper byte(0x0420,0x0520,0x0620,0x0720) first

and lower byte(0x0421,0x0521,0x0621,0x0721) later to get the correct value.

Ex) In case of 2048(0x0800) in S0_TX_FSR,

0x0420

0x0421

0x08

0x00

Total size can be decided according to the value of TX Memory Size Register. In the process of

transmission, it will be reduced by the size of transmitting data, and automatically increased

after transmission finished.

W5100 Datasheet(PDF) 34 Page - WIZnet Co., Ltd