The worst transmission speed of USB 2.0 Interface

[uzinei]

I'm designing an audio data transfer circuit using USB 2.0 interface.
I use the Cypress USB tranceiver.
I want to know the worst case transmission speed of USB 2.0.
I already read USB 2.0 Specification, but I cannot found any
information about that.
In USB 2.0 spec., there are only information about Maximum data rate,
480Mbit per sec.
So, please answer about the worst transmission speed of USB 2.0.
Thanks for any help with this.

uzinei

 

[Jim Macklin]

0 as in zero, being the worst.

USB 1.0 is 1.2 Mbit and 1.1 is 12.0 Mbit.


| I'm designing an audio data transfer circuit using USB 2.0
interface.
| I use the Cypress USB tranceiver.
| I want to know the worst case transmission speed of USB
2.0.
| I already read USB 2.0 Specification, but I cannot found
any
| information about that.
| In USB 2.0 spec., there are only information about Maximum
data rate,
| 480Mbit per sec.
| So, please answer about the worst transmission speed of
USB 2.0.
| Thanks for any help with this.
|
| uzinei
|

 

[uzinei]

Thanks for your answer. I think my question is not enough. So, your
answer is 0 Mbps.
I want to explain my question again. In 1394 interface, there is a
guaranteed minimum data rate, 100Mbps. Like this, is there a guaranteed

minimum data rate in USB 2.0 interface?
I assume that the device is high speed mode and there are only one
plugged USB 2.0 device in the host PC. In this conditon, is it possible

that my system have data rate higher than 2Mbit per sec when it is
received a certain audio data such as speech signal from microphone?

Jim Macklin 작성:

 

[Guest]

I want to explain my question again. In 1394 interface, there is a
guaranteed minimum data rate, 100Mbps. Like this, is there a guaranteed
minimum data rate in USB 2.0 interface?

Yes there is - if you have a isochronous endpoint, which means you
have to reserve bandwidth.
Without such reservation (bulk traffic) the minimum rate is 0.

I assume that the device is high speed mode and there are only one
plugged USB 2.0 device in the host PC. In this conditon, is it possible
that my system have data rate higher than 2Mbit per sec when it is
received a certain audio data such as speech signal from microphone?

If you need to guarantee certain bandwidth - just reserve it.
For more details: USB spec, books and so on.

--PA

 

[uzinei]

Thank you for your help!!

 

[antioch]

Try your quest here - very good forum as well

http://www.everythingusb.com/
Antioch

 

[uzinei]

Oh, it is very good information for me. Thank you!!!