Freescale Semiconductor StarCore SC140 - Manual (Page 529)

JSRD
SC140 DSP Core Reference Manual A-215
JSRD
Jump to a Subroutine Using a Delay Slot (AGU)
JSRD
Description
Executes the execution set in the delay slot, then pushes the next* PC (the PC of the execution set after the
delay slot) and SR onto the stack, and causes program execution to continue at the address defined by label
or Rn. In addition, the next* PC is stored in the RAS register, and RAS becomes valid. The destination
address cannot be in the middle of an execution set.
Status and Conditions that Affect Instruction
Status and Conditions Changed by Instruction
None.
Example
jsrd r6
Operation Assembler Syntax
(Next* PC)
→ (SP); SR → (SP + 4); SP + 8 → SP;
(Next* PC)
→RAS; label → PC
JSRD label {0
≤ label < 2
32 ,W}
(Next* PC)
→ (SP); SR → (SP + 4); SP + 8 → SP;
(Next* PC)
→ RAS; Rn → PC
JSRD Rn
JSRD label
Jumps to a memory location specified by an immediate 32-bit absolute address.
JSRD Rn
Jumps to a memory location contained in an address register (Rn). The value in Rn must be word-aligned.
Register Address Bit Name Description
SR[18] EXP Determines which stack pointer is used.
Instruction Comment
move.w #subroutine,r6 Places subroutine label in r6.
move.w #$35,d0 Places $35 in d0.
jsrd r6 move.w #$29,d1 Jump to subroutine, place $29 in d1.
inc d1 Increment executed in the delay slot, d1=$2A.
- - - - Skipped over.
- - - - Skipped over.
- - - - Skipped over.
subroutine Execution continues here at subroutine.
move.w #$16,d4