• State Accepted Answer
  • Locked Locked
  • Replies 2 replies
  • Subscribers 351 subscribers
  • Views 8411 views
  • Users 0 members are here
2025 survey

We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.

Options
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

"BX LR" causing INVPC Usage Fault exception

Sohaib

I have implemented a context switching code. For going back to privileged user mode after setting the return value in SP + 0x18 address, I am using BX LR instruction.

But code execution goes to HardFault handler and INVPC bit of USAFAULT register is set.

Following is the status of CPU registers just before executing the BX LR instruction. Address (0x100EFA34) saved at SP+0x18 is a valid address where I want PC to go

0