SWCU191 February 2022 CC1311P3 , CC1311R3 , CC2651P3 , CC2651R3 , CC2651R3SIPA
Exception return occurs when the processor is in handler mode and executes one of the following instructions to load the EXC_RETURN value into the PC:
EXC_RETURN is the value loaded into the LR on exception entry. The exception mechanism relies on this value to detect when the processor completes an exception handler. The lowest 4 bits of this value provide information on the return stack and processor mode. Table 6-2 lists the EXC_RETURN values with a description of the exception return behavior.
EXC_RETURN bits 31–4 are all set. When this value is loaded into the PC, it indicates to the processor that the exception is complete, and the processor initiates the appropriate exception return sequence.
EXC_RETURN[31:0] | Description |
---|---|
0xFFFF FFF0 | Reserved |
0xFFFF FFF1 | Return to handler mode Exception return uses state from MSP Execution uses MSP after return. |
0xFFFF FFF2 to 0xFFFF FFF8 | Reserved |
0xFFFF FFF9 | Return to thread mode: VTOR Exception return uses state from MSP Execution uses MSP after return. |
0xFFFF FFFA to 0xFFFF FFFC | Reserved |
0xFFFF FFFD | Return to thread mode Exception return uses state from PSP Execution uses PSP after return |
0xFFFF FFFE to 0xFFFF FFFF | Reserved |