usb function

[yalect]

thank you Mr Jan Axelson for Previous replys, I understand that each of D+ and D- works like out or in for type of transfer from begining at numeration, will not change after, and which Usually of them is in and other is out ?
thank you

[Jan Axelson]

No, low, full, and high speeds all use differential signaling. Differential zero is when D+ is logic low and D- is logic high as defined by the USB 2.0 spec. Differential one is when D+ is logic high and D- is logic low as defined by the USB 2.0 spec. Data travels in one direction at a time.

See 7.1.7 in the USB 2.0 spec.

[yalect]

Hi, you mean we can't use term of in and out for D+ or D- or clearly (Pin in) and (Pin out) not standard for example for usb 2.0 or I can say Dout and Din ?
many thank

[Jan Axelson]

No, Dout and Din are not accurate descriptions. Both lines carry data in both directions.

[yalect]

I understood that after numeration of device, D+ can works in and out data together and the same for D- or each one can works in direction ( during operating of  one device)   
regards

[Jan Axelson]

This might help in understanding how the interface works:

http://en.wikipedia.org/wiki/Differential_signaling