W5100 WIZnet, W5100 Datasheet - Page 62

• Manufacturer Part Number: W5100
• Description: Ethernet ICs 3-IN-1 ENET CONTR TCP/IP+MAC+PHY
• Manufacturer: WIZnet

Specifications of W5100

• Rohs: yes
• Product: Ethernet Controllers
• Data Rate: 10 Mb/s, 100 Mb/s
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 3 V
• Maximum Operating Temperature: + 80 C
• Package / Case: LQFP-80
• Ethernet Connection Type: 10Base-T, 100Base-TX
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Standard Supported: 802.3, 802.3u

© Copyright 2009-2010 WIZnet Co., Inc. All rights reserved.
6.3.1 Device Operations
The W5100 is controlled by a set of instruction that is sent from a host controller, commonly
referred to as the SPI Master. The SPI Master communicates with W5100 via the SPI bus which
is composed of four signal lines: Slave Select(/SS), Serial Clock(SCLK), MOSI(Master Out Slave
In), MISO(Master In Slave Out).
The SPI protocol defines four modes for its operation (Mode 0, 1, 2, 3). Each mode differs
according to the SCLK polarity and phase - how the polarity and phase control the flow of
data on the SPI bus.
The W5100 operates as SPI Slave device and supports the most common modes - SPI Mode 0
and 3.
The only difference between SPI Mode 0 and 3 is the polarity of the SCLK signal at the
inactive state. With SPI Mode 0 and 3, data is always latched in on the rising edge of SCLK and
always output on the falling edge of SCLK.
6.3.2 Commands
According to SPI protocol, there are only two data lines used between SPI devices. So, it is
necessary to define OP-Code. W5100 uses two types of OP-Code - Read OP-Code and Write
OP-Code. Except for those two OP-Codes, W5100 will be ignored and no operation will be
started.
In SPI Mode, W5100 operates in “unit of 32-bit stream”.
The unit of 32-bit stream is composed of 1 byte OP-Code Field, 2 bytes Address Field and 1
byte data Field.
OP-Code, Address and data bytes are transferred with the most significant bit(MSB) first and
least significant bit(LSB) last. In other words, the first bit of SPI data is MSB of OP-Code Field
and the last bit of SPI data is LSB of Data-Field. W5100 SPI data format is as below.
6.3.3 Process of using general SPI Master device
Write operation
Read operation
(According to SPI protocol)
Command
0xF0
0x0F
OP-Code Field
1111 0000
0000 1111
Address Field
2 bytes
2 bytes
Data Field
1 byte
1 byte
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