USB 1.1 device not correctly detected on 2.0 host controller

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ossian

This is a rephrasing of my Q on "plug and play device not detected". I have a
USB to serial cable compliant with 1.1 which installs perfectly on 1.1-based
systems (both XP and W98SE). On an XP-, USB 2.0-based system, it is not
correctly detected (registered as UNKNOWN with an incorrect ID). All
XP-systems have SP3. As the ID is not correctly reproduced the driver cannot
be found. I have always believed that the backwards compatibility of the 2.0
standard enables me to interconnect any combination of 1.1 and 2.0 just
losing speed and some advanced functions but this may not be true. Is the
cause to be found in the firmware for the device or is it a problem in the XP
environment?
TS
 
ossian said:
This is a rephrasing of my Q on "plug and play device not detected". I
have a
USB to serial cable compliant with 1.1 which installs perfectly on
1.1-based
systems (both XP and W98SE). On an XP-, USB 2.0-based system, it is not
correctly detected (registered as UNKNOWN with an incorrect ID). All
XP-systems have SP3. As the ID is not correctly reproduced the driver
cannot
be found. I have always believed that the backwards compatibility of the
2.0
standard enables me to interconnect any combination of 1.1 and 2.0 just
losing speed and some advanced functions but this may not be true. Is the
cause to be found in the firmware for the device or is it a problem in the
XP
environment?
Click to expand...

USB2 high speed mode is backardly compatible with USB1 fast and slow modes.
For technical reasons, the actual port hardware for high speed mode is
different to the other two modes. In normal use, the host and peripheral
communicate via the fast port hardware and then switch it out and reconnect
to the high speed hardware once credentials have been swapped. The user is
completely unaware that this happens.

The upshot of this is that if the USB1 port hardware is damaged, then it may
not operate correctly with USB1 peripherals wheras USB2 peripherals seem OK
because they use different hardware.

This is purely a speculative theory because I don't have access to your
hardware.
 
ossian said:
This is a rephrasing of my Q on "plug and play device not detected". I have a
USB to serial cable compliant with 1.1 which installs perfectly on 1.1-based
systems (both XP and W98SE). On an XP-, USB 2.0-based system, it is not
correctly detected (registered as UNKNOWN with an incorrect ID). All
XP-systems have SP3. As the ID is not correctly reproduced the driver cannot
be found. I have always believed that the backwards compatibility of the 2.0
standard enables me to interconnect any combination of 1.1 and 2.0 just
losing speed and some advanced functions but this may not be true. Is the
cause to be found in the firmware for the device or is it a problem in the XP
environment?
TS
Click to expand...

Here are a couple sources for the Microsoft UVCView program.
When a USB device is plugged in, the config information should be
visible on the right.

ftp://ftp.efo.ru/pub/ftdichip/Utilities/UVCView.x86.exe
http://www.users.on.net/~fzabkar/USB_IDs/UVCView.x86.exe

The copy I have here (which was available from the Microsoft
site at one time) has the following info:

File size is 167,232 bytes.
MD5sum is 93244d84d79314898e62d21cecc4ca5e

There is also a copy on web.archive.org, but it is missing the
last byte.

This is what the program output looks like.

http://www.die.de/blog/content/binary/usbview.png

Paul
 
Thanks. I tried the program which shows that the enumeration failed. It also
lists the Bus Speed as Low. I am left with a confusing state

- The USB device (USB to serial cable) works fine on XP Pro(SP3) system with
1.1 controllers only. The same relates to a W98SE-system, USB 1.1

- The device is NOT correctly enumerated ("blength of 0 incorrect") on a XP
Pro (SP3) system with an enhanced controller. The system however implements
other 1.1 devices as well as 2.0 devices. I tried several root hubs.

I have been looking for documentation to find out how the controllers
actually cooperate. If, as suggested by another reply to my Q, the low/full
speed controller is the first to operate then the device should be expected
to work as with the other 1.1-compliant systems. If, on the other hand the
high speed controller is the initial communicator AND furthermore has the
capability to collect ID info irrespective of the device standard then an
error in the 2.0-related part of the device firmware could explain the
problem and the low/fast speed controller would never be applied. As I
believe this to be the case I will try the cable on another 2.0-based XP
system when I find one.

To satisfy my own curiosity I would still like to understand the basics of
the combined controller functioning. So if any documentation is available
please let me know

TS
 
ossian said:
Thanks. I tried the program which shows that the enumeration failed. It also
lists the Bus Speed as Low. I am left with a confusing state

- The USB device (USB to serial cable) works fine on XP Pro(SP3) system with
1.1 controllers only. The same relates to a W98SE-system, USB 1.1

- The device is NOT correctly enumerated ("blength of 0 incorrect") on a XP
Pro (SP3) system with an enhanced controller. The system however implements
other 1.1 devices as well as 2.0 devices. I tried several root hubs.

I have been looking for documentation to find out how the controllers
actually cooperate. If, as suggested by another reply to my Q, the low/full
speed controller is the first to operate then the device should be expected
to work as with the other 1.1-compliant systems. If, on the other hand the
high speed controller is the initial communicator AND furthermore has the
capability to collect ID info irrespective of the device standard then an
error in the 2.0-related part of the device firmware could explain the
problem and the low/fast speed controller would never be applied. As I
believe this to be the case I will try the cable on another 2.0-based XP
system when I find one.

To satisfy my own curiosity I would still like to understand the basics of
the combined controller functioning. So if any documentation is available
please let me know

TS
Click to expand...

The available documentation is the USB2 standard.
But at 650 pages, you won't enjoy reading that :-)

http://www.usb.org/developers/docs

There is also a description here. This walks through enumeration,
until the device is ready to go. This is a much easier read. But
you can use the standard if you have any questions.

http://www.lvr.com/usbcenum.htm

Paul
 
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