Freescale Semiconductor StarCore SC140 - Manual (Page 211)

Hardware Loops
SC140 DSP Core Reference Manual 5-31
The following is an example of a short loop in one execution set.
Example 5-15. Short Loop, One Execution Set
The following is an example of a nested loop.
Example 5-16. Nested Loop
In Example 5-16, the LPMARKA bit of loop 0 is set because the SKIPLS instruction can skip over the
LPMARKB bit of loop 0.
The assembler sets the appropriate LPMARK bits, adding a prefix word with the loopstart or loopend
information, if necessary. In disassembly, these LPMARK bits (if used) appear preceding the normal
disassembled mnemonics of the set.
doensh0#$10
...
loopstart0
mac d0,d1,d2 move.w (r0)+,d0
loopend0
Loop body
LPMARKA SA, LA
dosetup0 _start0
dosetup1 _start1
doen0 #$10
...
loopstart0
_start0
bmset #$ff01,d0
doen1 d7
clr d2
skipls _end1
loopstart1
_start1
mac d0,d1,d2 move.w (r0)+,d0
add d5,d6,d4 move.w (r1)+,d5
sub d3,d2,d4 inc d5
mac d4,d5,d6 move.w (r0)+,d4
add d3,d4,d6 move.w (r1)+,d3
loopend1
_end1 inc d0
loopend0
_end0
SA
LA
Loop body 0
SA
LA
loop 0
loop 0
loop 1
loop 1
LPMARKB
LPMARKB
loop 0
loop 1
LPMARKA
loop 0
Loop
body
1