Verilog Ethernet: Work-in-Progress 100BASE-TX PHY

Re:Verilog Ethernet: Work-in-Progress 100BASE-TX PHY by nrclark on Friday March 17, 2023 @07:46AM (#35195727)

There are tons and tons of industrial products that use Ethernet for communication, but don't necessarily need a ton of data. Maybe a C&C machine, or a 3D printer, or an oscilloscope, or an automotive network. For any kind of command-and-control applications, 100 Mbit is more than fast enough. Even 10 Mbit would be plenty for lots of systems.

Around the house, you'll find 100BASE-T Ethernet on wired security cameras, televisions, printers, home-automation, and lots of other stuff too.

As a product designer, there are lots of reasons why I might want to put Ethernet on my widget. It's more robust than wifi, it's lower-power, and it's cheaper. It also has much longer range. I might also like to use Power-over-Ethernet to avoid the need for batteries or an electrical outlet.

Ethernet is also much easier to handle than wifi, from a software perspective. And there are lots of products don't really need more than 10-20 KB/sec of data throughput.

I worked on a product in 2022 that settled on 100BASE-T Ethernet as the right design fit (as a backup to wifi), and it was a great choice for the project. I'd make the same choice again today, for a similar system. 10BASE-T is pretty much gone at this point, but 100BASE-T is alive and well as the lowest common-denominator.

Pretty much all networking gear on the market supports 100BASE-T flawlessly, even if the rest of the devices on the network are 1000BASE-T or 2.5GBASE-T. Almost every laptop (or USB) Ethernet adapter also supports auto-negotiate and auto-crossover, meaning that you could plug your laptop right into some device's 100BASE-T port and start talking to it.

FPGAs are typically a little too pricy for consumer gear, but they're incredibly common in higher-margin commercial, industrial, and military equipment. And if your design already has an FPGA for some reason or another, why not use it to provide Ethernet as well? Cuts down on the number of chips you need to use in your design.

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Re:Verilog Ethernet: Work-in-Progress 100BASE-TX PHY by preisschild on Friday March 17, 2023 @08:14AM (#35196028)

Even most Smart-TVs still have only 100BASE-T ethernet connections, but this is still enough to stream a high-bitrate 4K DoVi/HDR10+ movie.

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Re:Verilog Ethernet: Work-in-Progress 100BASE-TX PHY by toast0 on Friday March 17, 2023 @10:15AM (#35197376)

Some 4k blu-rays will peak at greater than 100Mbps, so if you want to stream those without recompressing, you may need a big buffer or gigE.

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Re:Verilog Ethernet: Work-in-Progress 100BASE-TX PHY by mikepurvis on Friday March 17, 2023 @01:37PM (#35200240)

No one is bringing a raw Blu-Ray signal into the back of their TV over Ethernet though— Netflix's 4K streams cap out at around 16mbps, which is a tiny fraction of that.

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Re:Verilog Ethernet: Work-in-Progress 100BASE-TX PHY by toast0 on Friday March 17, 2023 @01:53PM (#35200453)

Well sure, cause there's not enough bandwidth :P otherwise, why not? The tv probably has a good enough decoder, just no disc drive.

Netflix streaming isn't exactly a high-bitrate movie either though.

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Re:Verilog Ethernet: Work-in-Progress 100BASE-TX PHY by wolrah on Friday March 17, 2023 @05:36PM (#35203239)

> No one is bringing a raw Blu-Ray signal into the back of their TV over Ethernet though— Netflix's 4K streams cap out at around 16mbps, which is a tiny fraction of that.

Who cares about internet streamers? Plenty of us definitely are bringing raw Blu-Ray signals in to the back of our TV over ethernet. Disk space is cheap, transcoding is slow and lowers the quality, so when I rip my movies I just do what the pirates call a "remux" where I keep the exact same audio and video streams as are on the disc and just slap them in to a MKV container for my convenience.

It's not super common for UHD Blu-Rays to crack 100mbit/sec but the spec allows for up to 144mbit/sec. I've casually looked in to it in the past and AFAIK Gemini Man is the current leader, with regular spikes to the 120mbit/sec range and one scene transition actually violates the spec by my count, hitting over 150mbit/sec.

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Re:Verilog Ethernet: Work-in-Progress 100BASE-TX PHY by mikepurvis on Sunday March 19, 2023 @01:17PM (#35221229)

Okay, fair. I think that's a use case that would likely be pretty far outside of what the manufacturer would be envisioning when they spec what kind of Ethernet port to put on the TV though— from their point of view it would be purely for firmware updates, spyware, and the built in streaming apps; anything more complicated than that will be coming from an external device through the HDMI port.

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Re:Verilog Ethernet: Work-in-Progress 100BASE-TX PHY by aix1 on Friday March 17, 2023 @02:50PM (#35201257)

Thanks for this - I now realise that I had 10BASE-T and 100BASE-T mixed up when I asked the question.

P.S. Too many generations... I still remember Token Ring and coax Ethernet fighting it out, and even today I run a mix of four different speeds at home, 1G/2.5G/10G and 25G. Everything's become a bit of a blur. :)

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