The Wiznet W5500 chip provides a hardware-based TCP/IP stack with support for 8 sockets, 32kB of circular buffer space, and a simple SPI interface for control and data. It includes the TCP/IP stack, ethernet MAC and PHY. It's an updated version the extremely popular W5100 used on many Arduino ethernet shields (incl. the official release) and Arduino boards with built-in ethernet.
The breakout board includes all the passives and a crystal needed to drive the chip. The W5500 does not include a pre-programmed MAC, you will need to obtain one for production use. As this is a 3.3V part and no level shifting is included, if you want to use this board with a 5V Arduino (ie, most of them) then you'll need to do some level shifting on the SPI interface yourself.
These may eventually be put into production, but for now it's purely for my own code development.
Untested, use at own risk.
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