3 ms·
> Or by a power flicker. Which can be caused by plugging in other devices too. That sounds pretty unlikely. Any references about this? The pulse needs to be pr
by vardump 8y ago
> Or by a power flicker. Which can be caused by plugging in other devices too.
That sounds pretty unlikely. Any references about this? The pulse needs to be pretty particular and the USB device needs to be powered.
- Dylan16807 8y agoPersonal experience, so not really. And it doesn't have to be very particular. Bad grounding can cause lots of ports to reset.
- vardump 8y agoSounds intentional, probably something sent by the USB host controller driver. I guess some hub chips might send it independently as well in some scenarios. USB bus resets (both D+ and D- down for 10ms) are a signal for the USB device software (well, firmware) to initialize device configuration. Basically to set configuration, data toggles and stalls to their defaults. (I've written USB device firmware.)
- Dylan16807 8y agoWell yes it's an intentional recovery from an error state, but the point is this can happen unexpectedly.