SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
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 has completed an exception handler. The lowest 5 bits of this value provide information on the return stack and processor mode. Table 1-20 shows the EXC_RETURN values with a description of the exception return behavior.
EXC_RETURN bits 31:5 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.FFE0 | Reserved |
0xFFFF.FFE1 |
Return to handler mode. Exception return uses floating-point state from MSP. Execution uses MSP after return. |
0xFFFF.FFE2 to 0xFFFF.FFE8 | Reserved |
0xFFFF.FFE9 |
Return to thread mode. Exception return uses floating-point state from MSP. Execution uses MSP after return. |
0xFFFF.FFEA to 0xFFFF.FFEC | Reserved |
0xFFFF.FFED |
Return to thread mode. Exception return uses floating-point state from PSP. Execution uses PSP after return. |
0xFFFF.FFEE to 0xFFFF.FFF0 | Reserved |
0xFFFF.FFF1 |
Return to handler mode. Exception return uses nonfloating-point state from MSP. Execution uses MSP after return. |
0xFFFF.FFF2 to 0xFFFF.FFF8 | Reserved |
0xFFFF.FFF9 |
Return to thread mode. Exception return uses nonfloating-point state from MSP. Execution uses MSP after return. |
0xFFFF.FFFA to 0xFFFF.FFFC | Reserved |
0xFFFF.FFFD |
Return to thread mode. Exception return uses nonfloating-point state from PSP. Execution uses PSP after return. |
0xFFFF.FFFE to 0xFFFF.FFFF | Reserved |