Freescale Semiconductor StarCore SC140 - Manual (Page 280)

7-30 SC140 DSP Core Reference Manual
Static Programming Rules
Example 7-51. DOENn instruction following DOENSHn Instruction
doensh0 #3
doen0 #3 dosetup0 _loop_start
; not allowed (SLF isn't reset)
nop
nop
_loop_start
loopstart0
move.l #0,d0
move.l #1,d0
move.l #2,d0
;instruction should be in the loop, but isn't!
loopend0
Example 7-52. LOOPEND between DOEN and LOOPEND
doen2 #3
dosetup2 L_1
nop
L_1
loopstart2
nop
nop
doen3 #3
;not allowed: problem created here
dosetup3 L_2
nop
nop
nop
loopend2
;problem becomes apparent here
nop
L_2
loopstart3
nop
nop
nop
loopend3
Example 7-53. Changing a loop type
doensh0 #3
doen0 #3
; not allowed to change loop type
dosetup0 _loop_start
nop
nop
_loop_start
loopstart0
move.l #0,d0
move.l #1,d0
move.l #2,d0
loopend0