Return from exception (agu), Description – Freescale Semiconductor StarCore SC140 User Manual
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SC140 DSP Core Reference Manual
ROR
RTE
Return From Exception (AGU)
RTE
Description
Note:
Because RTE does not use RAS, returning from a subroutine using RTE is illegal. The result is
undefined.
Status and Conditions that Affect Instruction
Status and Conditions Changed by Instruction
Operation
Assembler Syntax
(SP – 8)
→ PC
(SP – 4)
→ SR
SP – 8
→ SP
0
→ NMID
RTE
RTE
Returns from an exception routine. The program counter and status register are popped from the active
stack in memory, and program execution continues at the address specified in the PC. This instruction
cannot appear in an execution set with another AGU instruction or a set that uses IFT and IFF, IFT and
IFA, or IFF and IFA because RTE uses both AGUs. RTE does two simultaneous 32-bit long-word memory
accesses. Instructions that change SR cannot appear in the same set with this instruction.
Register Address
Bit Name
Description
SR[18]
EXP
Determines which stack pointer used and execution working mode.
Register Address
Bit Name
Description
SR[31:0]
Restores SR from stack.
EMR
[3]
NMID
Enables NMI.