I noticed, in another question, a comment regarding USB power states. I know that USB 2.0 negotiated power by tying the D+ and D- lines to specific voltages but I can't seem to find any information on USB 3.0 power state negotiation.
Since USB 3.0 has two sets of D+/D- lines, and I can't seem to find any information on this, does it either:
- Pull both sets of data lines to specific voltages
- Send actual data through to ask for power instead of setting static levels
- Just pull one set of data lines to the specific voltages?
- Or something else?
Bonus points if you can find the actual voltage levels or data for the different states.
Not as per USB Specification. The battery specification signals the "charger" via a short (low resitance) between
As in the USB 2.0 spec, look in the Standard Configuration Descriptor. The
bMaxPowerfield definition is updated in the 3.0/3.1 USB specs. From USB_3_1_r1.0.pdf, Table 9-21: