Datasheet

12 / 66 W5500 Datasheet Version1.0.9
HOST Interface
W5500 provides SPI (Serial Peripheral Interface) Bus Interface with 4 signals (SCSn,
SCLK, MOSI, MISO) for external HOST interface, and operates as a SPI Slave.
The W5500 SPI can be connected to MCU as shown in Figure 4 and Figure 5 according
to its operation mode (Variable Length Data / Fixed Length Data Mode) which will be
explained in Chapter 2.3 and Chapter 2.4.
In Figure 4, SPI Bus can be shared with other SPI Devices. Since the SPI Bus is
dedicated to W5500, SPI Bus cannot be shared with other SPI Devices. It is shown in
Figure 5.
At the Variable Length Data mode (as shown in Figure 4), it is possible to share the
SPI Bus with other SPI devices. However, at the Fixed Length Data mode (as shown in
Figure 5), the SPI Bus is dedicated to W5500 and can’t be shared with other devices.
Figure 4. Variable Length Data Mode (SCSn controlled by the host)
Figure 5. Fixed Length Data Mode (SCSn is always connected by Ground)
The SPI protocol defines four modes for its operation (Mode 0, 1, 2, 3).Each mode
differs according to the SCLK polarity and phase. The only difference between SPI
Mode 0 and SPI Mode 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.
SPI MASTER
MCU
(External Host)
SPI SLAVE
W5500
SCSn
SCLK
MOSI
MISO
SCSn
SCLK
MOSI
MISO
SPI MASTER
MCU
(External Host)
SPI SLAVE
W5500
SCSn
SCLK
MOSI
MISO
SCSn
SCLK
MOSI
MISO