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USB 2.0 device driver communication
06-30-2011, 06:27 PM
Post: #1
USB 2.0 device driver communication
Hi Friends,

Please help me out. I am facing some issues with USB2.0 OTG driver communication. Actually we designed a micro controller and in which we have USB port supported which we bought from one of the vendor. Vendor only provided the device drivers for the USB.

Windows will load the device driver, after performing the following 9 steps.

1. The host or hub detects the connection of a new device via the device's pull up resistors on the data pair. The host waits for at least 100ms allowing for the plug to be inserted fully and for power to stabilize on the device.
2. Host issues a reset placing the device is the default state. The device may now respond to the default address zero.
3. The MS Windows host asks for the first 64 bytes of the Device Descriptor.
4. After receiving the first 8 bytes of the Device Descriptor, it immediately issues another bus reset.
5. The host now issues a Set Address command, placing the device in the addressed state.
6. The host asks for the entire 18 bytes of the Device Descriptor.
7. It then asks for 9 bytes of the Configuration Descriptor to determine the overall size.
8. The host asks for 255 bytes of the Configuration Descriptor.
9. Host asks for any String Descriptors if they were specified.

At the end of Step 9, Windows will ask for a driver for the device (by requesting Interface descriptor). It is then common to see it request all the descriptors again before it
issues a Set Configuration request.

In our test we are able to proceed till step 5. But after step 5 we are not giving a proper response.

Can anyone tell what could be the problem.

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07-04-2011, 12:25 AM
Post: #2
RE: USB 2.0 device driver communication
You would have better luck getting an answer for this on some dedicated system programming forum I'm sorry, this is far beynd the scope of Device Doctor which is a software for identification of existing drivers, we are not involved in driver coding either.

Good luck!
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