2.15.2. Leaving an exception

When an exception has completed, the exception handler must move the LR, minus an offset to the PC. The offset varies according to the type of exception, as Table 2.12 shows.

Typically the return instruction is an arithmetic or logical operation with the S bit set to 1 and rd = r15, so the core copies the SPSR back to the CPSR.

Note

The action of restoring the CPSR from the SPSR, automatically resets the T bit and J bit to the values held immediately prior to the exception. The A, I, and F bits are also automatically restored to the value they held immediately prior to the exception.

Copyright © 2006-2009 ARM Limited. All rights reserved.ARM DDI 0344I
Non-Confidential