W5100 datasheet(62/72 Pages) WIZNET

62 / 72 page

Value

Symbol

Description

0x00

It performs the selection of Indirect bus I/F mode, address

automatic increase. Refer to “4. Register Description” for more

detail.

0x01

0x02

IDM_AR0

IDM_AR1

Indirect bus I/F mode address Register

Big-endian use only

· In case of Big-endian ordering

0x01

0x02

IDM_AR0 : MSB

IDM_AR1 : LSB

Ex) In case of reading S0_CR(0x0401),

0x01(IDM_AR0)

0x02(IDM_AR1)

0x04

0x01

0x03

IDM_DR

Indirect bus I/F mode data Register

In order to read or write the internal register or internal TX/RX Memory,

1. Write the address to read or write on IDM_AR0, 1.

2. Read or Write IDM_DR.

In order to read or write the data on the sequential address, set AI bit of MR(Mode Register).

With this, user performs above 1 only one time. Whenever read or write IDM_DR, IDM_AR , the

value is automatically increased by 1. Therefore, the value can be processed on the

sequential address just by continuous reading or writing of IDM_DR.

6.3 SPI (Serial Peripheral Interface) mode

Serial Peripheral Interface Mode uses only four pins for data communication.

Four pins are SCLK, /SS, MOSI, MISO.

At the W5100, SPI_EN pin is used for SPI operation.

W5100 Datasheet(PDF) 62 Page - WIZnet Co., Ltd