* Question
| What are the two special features of Rl4 in terms of structure? |
* Answer
| 1 When a subroutine is called with the BL instruction, the return address is automatically stored in Rl4.
2 When an abnormal interrupt occurs, care should be taken to ensure that the exception handler does not destroy LR, because LR stores the return address of the exception handler, that is, saves the return address of the exception handler to the exception mode register corresponding to LR. |
COMMENTS