Rtstk, Restore pc from stack (agu) – Freescale Semiconductor StarCore SC140 User Manual

Page 688

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A-374

SC140 DSP Core Reference Manual

RTSTK

RTSTK

Restore PC from Stack (AGU)

RTSTK

Description

Status and Conditions that Affect Instruction

Status and Conditions Changed by Instruction

Operation

Assembler Syntax

(SP – 8)

→ PC

SP – 8

→ SP

RTSTK

RTSTK

Forces a return from a subroutine or exception by restoring the program counter (PC) from the active stack
in memory. The restore to the PC is not from the RAS register, even if RAS is valid. The implicit pop is
done before the execution set in the delay slot is executed. The stack pointer decrements by 8 and RAS
becomes invalid. This instruction can be used to bypass RAS (for example, when the return address is
changed directly on the stack). RTSTK does one 32-bit long-word memory access.

Register Address

Bit Name

Description

SR[18]

EXP

Determines which stack pointer is used.

Register Address

Bit Name

Description

EMR

[3]

NMID

Cleared .

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