DSP Core Reference Manual

RTSTK

SC140 DSP Core Reference Manual A-375

Example

rtstk

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 Restore the new value lbl to PC.

move.l #$16,d5 This instruction skipped.

lbl move.l #$16,d6 Continue executing here.

Instruction Words

Cycles

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

Type Opcode

15 8 7 0

RTSTK 1 5/6 4 1001111101110101