STM CircleOS forum / Usb problem without Circle OS

azinkl · 2009-12-14 09:30:56

Hello,

I want to develop an application without using Circle OS, in which the user can choose between different usb devices. I tried to run the mass storage device example from ST library, but it doesn't work.
I get an interrupt for RESET, which should be hardware-driven on primer side, but not for SOF(Start Of Frame) or CTR(Correct Transfer). My Windows XP shows the device as "Enumeration Failed".
If I use the implementation of Circle OS Mass Storage it works and I get RESET, SOF and CTR interrupts.
I have reduced complete Circle OS on the usb stuff. now the source code is nearly the same than the example of ST and it still works.
The only difference between both applications is that the example of ST uses an newer version of USB library. But I think that should be no problem(I diffed the source and found no significant differences).

Do you have some hints, what the problem could be?

ciao
azinkl

(sorry for my bad english, I am German ;-) )

yrt · 2009-12-14 12:43:26

Hi,

With USB, the mostly met problem is the USB clock configuration.
Check if your USB clock is well configured to 48MHz (with Ride you can visualize the "Reset Clocks" registers in debug tab).

You can also take a look to the specific USB ST forum : http://www.st.com/mcu/forumsid-12.html

Yves

azinkl · 2009-12-16 09:00:13

Hello,

Thanks for your fast reply.
It was the USB clock, but unfortunately Ride7 shows the wrong value for clock speed.
I orientated on the shown value in Ride7.
But with the circle os settings Ride7 shows 32 MHz and it works.

Thanks for your help.

ciao
azinkl

yrt · 2009-12-16 12:46:14

Hi,

The frequency displayed by Ride are calculated from the value of the HSE (external quartz), that should be indicated by the user, in the project parameter "Rlink configuration/Advanced options/Crystal frequency".
This value is 8 MHz by default, and the Primer are equiped with a 12 MHz crystal. So the difference !

Yves

# 1 2009-12-14 09:30:56 Usb problem without Circle OS

Usb problem without Circle OS

# 2 2009-12-14 12:43:26 Usb problem without Circle OS

Re: Usb problem without Circle OS

# 3 2009-12-16 09:00:13 Usb problem without Circle OS

Re: Usb problem without Circle OS

# 4 2009-12-16 12:46:14 Usb problem without Circle OS

Re: Usb problem without Circle OS

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