There
are several hardware setup programs that warn the user, "This device
requires a USB 1.1 compliant host controller."
We
receive a lot of inquiries regarding this misleading statement.
The
following Question and Answer is intended to clarify the issue.
What
is USB Specification, version 1.1?
USB
specification 1.1 was written to provide further clarification and additional
features for USB devices and hubs. The new specification was written to help hardware makers build better USB
product. USB specification 1.1 was written for and only effects USB
peripheral devices.
Did
the specification for the host controller change from version 1.0 to 1.1?
NO.
The host controller portion of the USB specification is unchanged in the 1.1
revision. As part of a complete USB specification, specification 1.1
included the UNCHANGED 1.0 USB host controller specification. There is NO
difference in the host controller specification in version 1.1.
How
did all this disinformation get started?
A
flaw in an early OHCI, USB host controller may be the source. The bug
affected mass storage devices, printers, scanners, and other devices that
require data integrity. The OHCI flaw
has been corrected by Microsoft with a work around in Windows98 SE, v
4.10.2222a.
So
what you're saying is, a 1.1 host controller is the exact same thing as a 1.0
host controller.
Yes!
Please
note: Windows98 First Release versions do not provide the work around for
the OHCI/VHDL core
bug.
For
the vast majority of users, the USB
Specification 1.0 vs. 1.1 controversy is a NON-ISSUE.
Jeff
Roberts
USBMan
04/25/2002
