ColdFire/68K Microcontrollers and Processors中的主题 Re: Continuously receiving get_descriptor in usb

Continuously receiving get_descriptor in usb

salman83 — Tue, 04 Sep 2012 21:47:49 GMT

Hi,

I am trying to program MCF52259 demo kit micro controller. At the moment I am stuck with USB Endpoint 0. When I connect my usb, I get interrupt and then asked for Get_Descriptor. I send the device descriptor then it resets but after resetting, it again asks for device descriptor instead of issuing Set_Address command.

What could be the cause of the problem.

Here is the sequence of events that I encountered.

RESET

SETUP - Get_Descritpor

OUT

RESET

SETUP - Get_Descritpor

OUT

RESET

SETUP - Get_Descritpor

OUT

Re: Continuously receiving get_descriptor in usb

eckhard — Wed, 05 Sep 2012 17:57:34 GMT

Hello,

maybe you have a problem with overlapping Interrupt Priorities.

Have a look at this http://mcuoneclipse.wordpress.com/2012/04/22/trapspitfalls-overlapping-interrupt-priorities/

Eckhard

Re: Continuously receiving get_descriptor in usb

salman83 — Thu, 06 Sep 2012 17:21:22 GMT

Thanks for the reply.

I checked all the interrupt handlers. I am not receiving any interrupt apart from USB.

But still I am getting the same problem.

I looked into the sample programs on the internet but can't find whats the problem.

Any help will be highly appreciated.

Regards.

Re: Continuously receiving get_descriptor in usb

swapnilmisal — Fri, 28 Sep 2012 11:43:03 GMT

Hello,

try using a software usb sniffer for detail packet transfer.

find whose creating problem 1)is it PC who cannot detect ACK signals from MCF52259

2) Or device which cannot send descriptor in required format.

Download USB Monitor

Swapnil.