RFE — Return from Exception

Instruction Word

Slot
Inst
6
3
6
2
6
1
6
0
5
9
5
8
5
7
5
6
5
5
5
4
5
3
5
2
5
1
5
0
4
9
4
8
4
7
4
6
4
5
4
4
4
3
4
2
4
1
4
0
3
9
3
8
3
7
3
6
3
5
3
4
3
3
3
2
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9876543210
Format x24 - 24 bit(s) 0
RFE 000000000011000000000000

Assembler Syntax

RFE

Description

(please consult the Xtensa ® Instruction Set Architecture Reference Manual for any cross references and additional information)

RFE returns from either the UserExceptionVector or the KernelExceptionVector. RFE sets PS.EXCM back to 0, and then jumps to the address in EPC[1]. PS.UM and PS.WOE are left unchanged.

RFE is a privileged instruction.

Operation

if CRING != 0 then
	Exception (PrivilegedCause)
else
	PS.EXCM ← 0
	nextPC ← EPC[1]
endif

Exceptions

EveryInst Group (see EveryInst Group:)GenExcep(PrivilegedCause) if Exception Option

Implementation Pipeline

In Out
EPC1 Estage PSEXCM Estage