AnsweredAssumed Answered

STM32F105 - USB OTG - BusFault at 0x1fff7a10

Question asked by hediger.claudio.004 on Jan 7, 2018
Latest reply on Jan 7, 2018 by hediger.claudio.004



I try to implement a VCP on a STM32F105RB with the STM32_USB-Host-Device_Lib_V2.2.0

I was able to compile the Code sucessfully.


My Hardwareconfiguration is the following:

Mini USB directly (without series resistors) to D+ and D- of the STM32. +3.3V to PA9 (for BusSensing)


After debugging start in atollic, the host detects a new device but it is not listed in the device manager.

After few seconds, i get a BusFault on the STM. The BFARVALID is set and the BFAR is 0x1FFF 7A10

This is interessting, since the Addressspace between 0x0804 0000 - 0x1FFF AFFF is reserved.

If i restart the firmware 2-3 times (NOT the debugging process, only do a soft reset not a hard reset) and click run again, then it detects the VCP correctly after some tries. It shows a not working COM9 and a working COM10 in the device manager. And it does not end up in the bus fault anymore.


Can anybody help me solve this problem?



Attached are the Registers at BusFault and the Dissassembly.