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Comment by userbinator | Hacker News Reader

The lack of shielding is rarely any problem. Two oscillators is not better than one, since PLLs can generate the required clocks (480MHz = 25 / 5 x 96, 100MHz = 25 x 4, 125MHz = 25 x 5); SMSC has some USB/Ethernet solutions that use the same 25MHz frequency.

> The Windows drivers are the exact same digitally signed ones that Microsoft distributes through Windows Update

AFAIK there is a standard device class for "USB ethernet controllers", so any chipset that conforms to it will work fine with the standard drivers.

As for the unmarked chip - many IC companies are not averse to creating custom designs for a specific customer (and marking it however you want) if you're willing to buy enough. I don't think it's ASIX since they don't have the single 25MHz clock source; more willing to bet on Microchip or SMSC.

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You're spot on about the PLL stage, a few people on Reddit pointed the same thing out when I first posted it. Makes sense, although I still think it's interesting they added it internally to an otherwise (apparently) cloned design.

You're also right that USB CDC does provide the option for a generic USB Ethernet device, however this silicon is ASIX-specific (not just the USB IDs.) ASIX's Windows drivers include their own system driver binaries, and the ASIX Linux driver has a lot of ASIX-specific stuff in it.

I think it's kind of possible ASIX made this themselves as some kind of no-name branded unadvertised market segmentation effort. I can't understand what their rationale would be exactly but hardware companies do unusual things sometimes...

If you go only on the definition of a clone being "compatible interface", then there are tons of other examples of that in the electronics industry - it's more commonly known for simpler parts like voltage regulators (how many companies make a '7805?), opamps, transistors, etc. but also occurs with more complex ones too.

IC companies make unadvertised products all the time, for anyone who is willing to buy enough... look at Apple's Lightning cable and TI's BQ2025, for instance.

> I don't think it's ASIX since they don't have the single 25MHz clock source; more willing to bet on Microchip or SMSC.

Note that it identifies itself to the system as ASIX, though. Of course, it could be that other companies actually have a license to make ASIX things...

USB descriptors are programmed in the EEPROM, so they could've made it identify itself as anything they wanted. If you can dump the EEPROM, that can provide more clues - the configuration format does differ between manufacturers.

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