W5100S datasheet(48/110 Pages) WIZNET

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W5100S Datasheet Version1.2.5

S0_RXBUF_SIZE(0x041E)

0x08

3.2.14 Sn_TXBUF_SIZE (SOCKET n TX Buffer Size Register)

[RW] [0x001F+0x0100*(n+4)] [0x02]

Sn_TXBUF_SIZE configures SOCKET n TX Buffer Size as 0, 1, 2, 4 and 8 Kbytes. TX Memory is

sequentially allocated from SOCKET 0 to SOCKET 3. The total sum of Sn_TXBUF_SIZE must not

be exceeded 8 Kbytes. Sn_TXBUF_SIZE can also be configured by RMSR.

Value (Dec)

Buffer size

0KB

1KB

2KB

4KB

8KB

Ex) S0_TXBUF_SIZE= 4KB

S0_TXBUF_SIZE(0x041F)

0x04

3.2.15 Sn_TX_FSR (SOCKET n TX Free Size Register)

[RO] [0x0020+0x0100*(n+4), 0x0021+0x0100*(n+4)] [0x0800]

Sn_TX_FSR indicates SOCKET n TX Free Buffer Size.

In UDP, IPRAW and MACRAW mode,

Sn_TX_FSR = | Sn_TX_WR(1) – Sn_TX_RD(2) | + 1

In TCP mode,

Sn_TX_FSR = | Sn_TX_WR – Internal Pointer(3) | + 1

(1) SOCKET n TX Write Pointer Register

(2) SOCKET n TX Read Pointer Register

(3) TCP ACK Pointer managed by W5100S

Data to be stored in SOCKET n TX Buffer must not be bigger than Sn_TX_FSR.

Ex) S0_TX_FSR = 1024 (0x0400)

S0_TX_FSR0(0x0420)

S0_TX_FSR1(0x0421)

0x04

0x00

3.2.16 Sn_TX_RD (SOCKET n TX Read Pointer Register)

[RO] [0x0022+0x0100*(n+4), 0x0023+0x0100*(n+4)] [0x0000]

Sn_TX_RD indicates the last Data Address in SOCKET n TX Buffer Block after transmitting.

Sn_TX_RD is initialized by Sn_CR [OPEN]. On TCP Mode, Sn_TX_RD is re-configured in TCP

Connection Process. By Sn_CR [SEND] and Sn_CR [SEND_MAC], Sn_TX_WR (SOCKET n TX Write

W5100S Datasheet(PDF) 48 Page - WIZnet Co., Ltd