Freescale Semiconductor StarCore SC140 - Manual (Page 475)

DOSETUPn
SC140 DSP Core Reference Manual A-161
DOSETUPn
Setup Long Loop
DOSETUPn
Start Address (AGU)
Description
Status and Conditions that Affect Instruction
None.
Status and Conditions Changed by Instruction
None.
Example
dosetup1 _label
Operation Assembler Syntax
PC + displacement
→ SAn
DOSETUPn label
DOSETUPn label
This instruction is required for initialization of a long loop, not short loops. In case the loop is nested, the
DOSETUPn instruction can be placed outside the enveloping loop as long as SA (Start Address) is not
changed by instructions in the loop. DOSETUPn loads a loop start address register (SAn). The label is
placed at the beginning of the loop. The encoded value in the DOSETUP instruction is a PC relative
displacement calculated by the assembler and linker from the label. The start address placed in SAn is the
absolute address of the label. The DOSETUPn instruction is redundant with the LOOPSTART assembler
directive, both of which define SA. In case of a conflict between the two, SA is defined by DOSETUPn.
Register/Memory Address Before After
(displacement) $101E
PC $0000 0002
SA1 $0000 1020