PORTS Forum

Ports and Interfaces => USB => Topic started by: titan_amit on May 15, 2011, 04:54:50 am

Title: how do we recover clock in usb
Post by: titan_amit on May 15, 2011, 04:54:50 am

There is no clock input given to a usb device, so how does a usb device recovers clock information?

Title: Re: how do we recover clock in usb
Post by: Pat Crowe on May 15, 2011, 09:51:58 am

A digital phase lock loop.

Title: Re: how do we recover clock in usb
Post by: Chris on May 16, 2011, 03:40:15 am

When transmiting date on bus,the device can recover clock from the data stream.
In usb1.1 and usb2.0,The Spec used bit stuff to ensure receiver's clock recover.
In usb3.0,USB Spec used 8b/10b code and decode technic to ensure clock recovery.