Example, Instruction formats and opcodes, Rtstkd – Freescale Semiconductor StarCore SC140 User Manual

Page 691

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RTSTKD

SC140 DSP Core Reference Manual

A-377

Example

rtstkd

Instruction Formats and Opcodes

Instruction

Comment

- - -

jsr SUB

Jump to subroutine at SUB. Push the PC and SR onto the
stack.

- - -

Skip over these instructions.

SUB MOVE.w

#$16,d4

Execute the subroutine here.

- - -

move.w #lbl,(SP-8)

Change the original value in the stack for PC to lbl.

rtstk move.l #$35,d1
inc d1

Restore the new value lbl to PC. Load $35 into d1. Incre-
ment d1 to $36, the delay slot instruction.

move.l #$16,d5

This instruction skipped.

lbl

move.l #$16,d6

Continue executing here.

Instruction

Words

Cycles

1

Note 1: RTSTKD uses 5 cycles if shadow SP is valid. RTSTKD uses 6 cycles if the shadow SP is not valid. To

get the correct cycle count for this instruction, subtract the execution time used by the execution set in the
delay slot. The cycle count for this instruction cannot be less than 2 cycles.

Type

Opcode

15

8

7

0

RTSTKD

1

5/6

4

1

0

0

1

1

1

1

1

0

1

1

1

0

1

0

0

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