Hi,
I'm having some trouble working with the usb-host controller of an AT91SAM9261 mcu. The CPU stops executing my code if I try to read from the usb-host (address 0x500000). When the mcu crashes it doesn't seem to be jumping to any of the exception-handlers and if I try using the debugger I get an error message that the debugger is "unable to halt the cpu", and then the Debug-message-window is flooded with error messages.
It seem to be related to the RL-RTX library since it seem to work better (it still crashes in certain cases) if I comment out the os_sys_init()-function and don't start the threads.
Does the RL-RTX-lib protect some memory areas or maybe overrides an exception vector or something that might cause this behavior?
I would appreciate any help or suggestions.
Best Regards /Ake Forslund
The hardware isn't very exotic, and further testing has shown that there is problem with the initiation of the clocks for the host-controller (When reading the status registers none of the USB-host related clocks are reported active). I'm doing something wrong or maybe not setting a register that I should be setting. I have contacted the support at Atmel and they has sent me contact information for a person that has worked with the same hardware as I am working with now, hopefully he has some insight into this problem and can tell me what I'm doing wrong.
Thank you for your help.