The EM9191 product technical specification is very confusing regarding USB 2.0 capability for the interface to the host. I understand that USB 2.0 is not officially tested or commercially supported, as stated. But, page 23 and page 30 both indicate that the USB 3.1 interface is USB 2.0 backward-compatible, which makes sense and indicates that USB 2.0 functionality is included. But then page 30 states, “Important: Host support for USB 3.1 signals is required when USB is selected as the host interface.” This does not align with what was previously stated (2.0 backwards compatibility). Can you please provide clarity on this?
Thanks!
it means your host platform should have USB3
Got clarification from Semtech. In case it is helpful to others – USB 2.0 functionality is included, as you would expect. It is not officially supported or tested, as indicated in the spec sheet. And, of course, USB 2.0 will be a bottleneck for throughput since it is only 480 Mbps.