Table 5-6 Exception Return Behavior - ARM Cortex-M3 Technical Reference Manual

Exceptions
5-18
When used in this way, the value written to the PC is intercepted and is referred to as
the EXC_RETURN value. EXC_RETURN[3:0] provides return information as
defined in Table 5-6.
EXC_RETURN[3:0]
0bXXX0
0b0001
0b0011
0b01X1
0b1001
0b1101
0b1X11
RESERVED entries in this table result in a chained exception to a UsageFault.
If an EXC_RETURN value is loaded into the PC when in Thread mode, or from the
vector table, or by any other instruction, the value is treated as an address, not as a
special value. This address range is defined to have Execute Never (XN) permissions,
and will result in a MemManage fault.
Copyright © 2005, 2006 ARM Limited. All rights reserved.

Table 5-6 Exception return behavior

RESERVED
Return to Handler Mode
Exception return gets state from the Main stack
On return execution uses the Main Stack
RESERVED
RESERVED
Return to Thread Mode
Exception return gets state from the Main stack
On return execution uses the Main Stack
Return to Thread Mode
Exception return gets state from the Process stack
On return execution uses the Process Stack
RESERVED
ARM DDI 0337B