How quickly can you get from tinkering with Ethernet on Arduino to e.g. creating 10Gbit router with FPGA?
I don't want to sound bad, but it's a bit like writing BASIC programs on C64 today? Fun, entertaining, but is it actually useful for developing skills in this domain?
If there is ambition to work at high speeds and feeds I would jump straight to FPGA and bypass anything like this WIZnet ASIC which simultaneously does too much and too little to be relevant to that pursuit (but it is great if you have the exact use case of wanting to add Ethernet to an existing MCU).
Doing Ethernet at the logic design level is a lot of hard work but it isn't exactly a mystery at this point unless you are working on next generation speeds and feeds. A book on digital design, a book on HDL of choice, and a willingness to read specifications (IEEE 802, SFP MSA) and datasheets (FPGA MAC, third party PHY chips) is what you need to be successful.
NetFPGA collates a lot of teaching materials and example code for this but the major FPGA vendors also have relevant works. Ignore any suggestions that you need formal education in the space, it's simply not true.
At a minimum, 4 years in college. The things required to do the 10gbit router are things you will never run into, learn, or be challenged by bit banging SPI with an existing Ethernet peripheral.
Pretty much by definition, the engineering required for "high performance" anything is completely divorced from the knowledge required to implement basic systems.
>Fun, entertaining, but is it actually useful for developing skills in this domain?
Yes. Yes, always. You always learn, no matter what you do. Why build an 8-Bit CPU if you we have very complex 64 bit ones nowadays? Because the fundamentals are mostly the same.
I don't want to sound bad, but it's a bit like writing BASIC programs on C64 today? Fun, entertaining, but is it actually useful for developing skills in this domain?