W5300 datasheet(84/128 Pages) WIZNET

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Sn_TTLR (SOCKETn TTL Register) [R/W] [0x0821E+0x40n/0x21E+0x40n] [0x80]

It sets TTL(Time To Live) field of IP header at the IP layer. It should be set before OPEN

command. Refer to http://www.iana.org/assignments/ip-parameters.

Ex) Sn_TTLR = 128 (0x80)

Sn_TTLR(0x0821E+0x40n/0x21E+0x040n)

Sn_TTLR0(0x0821E+0x40n/0x21E+0x040n)

Sn_TTLR1(0x0821F+0x40n/0x21F+0x040n)

Reserved

0x80

Sn_TX_WRSR (SOCKETn TX Write Size Register) [R/W]

[0x08220+0x40n/0x220+0x40n] [0x00000000]

It sets the byte size of the data written in internal TX memory through Sn_TX_FIFOR.

It is set before SEND or SEND_MAC command, and can't be bigger than internal TX memory

size set by TMSRn.

W5300 automatically divides the data in the unit of Sn_MSSR in case of 'Sn_TX_WRSR >

Sn_MSSR' at the TCP or UDP mode. In other modes, Sn_TX_WRSR should not be set bigger

than Sn_MSSR.

Ex1) Sn_TX_WRSR = 64KB = 65536 = 0x00010000

Sn_TX_WRSR(0x08220+0x40n/0x220+0x040n)

Sn_TX_WRSR0(0x08220+0x40n/0x220+0x040n)

Sn_TX_WRSR1(0x08221+0x40n/0x221+0x040n)

Reserved

‘1’

Sn_TX_WRSR2(0x08222+0x40n/0x222+0x040n)

Sn_TX_WRSR3(0x08223+0x40n/0x21D+0x040n)

0x00

Ex2) Sn_TX_WRSR = 2017 = 0x000007E1

Sn_TX_WRSR(0x08220+0x40n/0x220+0x040n)

Sn_TX_WRSR0(0x08220+0x40n/0x220+0x040n)

Sn_TX_WRSR1(0x08221+0x40n/0x221+0x040n)

Reserved

‘0’

Sn_TX_WRSR2(0x08222+0x40n/0x222+0x040n)

Sn_TX_WRSR3(0x08223+0x40n/0x223+0x040n)

0x07

0xE1

W5300 Datasheet(PDF) 84 Page - WIZnet Co., Ltd