Anyone make a true USB 3.0 to USB 2.0 converter?

[NeoPTLD]

There was a true USB 2.0 to USB legacy converter that connects as USB 2.0 on uplink and provisions four USB 1.1 12Mbps transceivers on the downlink enabling four USB 1.1 devices to operate at 12Mbps each for a total of 48Mbps without causing the uplink to shift down to USB 1.1.

In essence, it's a four channel USB 1.1 host adapter with USB 2.0 uplink.
The chip is Cypress CY7C65640A
http://www.cypress.com/file/136046/download

Is there something like this that provisions USB 2.0 from 3.0/3.1

 

[Insert_Nickname]

Is there something like this that provisions USB 2.0 from 3.0/3.1

I don't think I have seen such. Most common USB3 hub chipsets do feature what you're describing however.

 

[mikeymikec]

I'm confused, doesn't USB do this already?

 

[StefanR5R]

Insert_Nickname, are you sure? So far I assumed that USB 3 hubs simply consist internally of a USB 2 hub and an additional, physically separate SuperSpeed hub. The USB 2 hub exclusively serves the USB 1/2 uplink and downlinks, and the SuperSpeed hub exclusively serves the SuperSpeed uplink and downlinks. Isn't this how current USB 3 hubs work?

NeoPTLD is asking for a device with store-and-forward and protocol conversion functionality:

• Pick up SuperSpeed transmissions from uplink, convert them to high-speed or less (and strip CRCs from the packets) and transmit it to the respective downlink.
• Vice versa, receive high-speed or slower transfers from a downlink, add CRCs, retransmit it at SuperSpeed to the uplink.
• The device needs to wrap these transmissions into USB 2 transactions at the downlinks and SuperSpeed transactions at the uplink (receive request from host, generate response to host).
  
• And I suspect that such a device would also have to intercept and modify negotiations between host and endpoints at a higher level, beyond the usual USB 2 physical layer speed negotiation during reset.

I.e. such a device needs to be a full-blown USB 2 host and USB 3 target in combination, with physical layer, link layer, and transaction layer functionality.