Freescale Semiconductor StarCore SC140 - Manual (Page 290)

7-40 SC140 DSP Core Reference Manual
Static Programming Rules
Rule L.C.11
A delayed COF instruction is not allowed at LA-3 of a long loop.
Example 7-72. Delayed COF at LA-3 of a Long Loop
jmpd_dest ;not allowed
nop
nop
nop
loopend0
Rule L.C.12
A delayed COF instruction is not allowed at SA-1 of a short loop.
Example 7-73. Delayed COF at SA-1 of a Short Loop
jmpd _dest ;not allowed
loopstart0
nop
loopend0
7.5.11 General Looping Rules
Rule L.G.3
A MOVE-like instruction that reads the SR register is not allowed at the (LA-3), (LA-2), (LA-1), and LA
of any long loop.
Example 7-74. SR Read to LA of Any Long Loop
dosetup1 label1
doen1 #5
loopstart1
label1
inc d1
move.l sr,d0
;not allowed
inc d2
move.l #mem_l1,r1
move.l #mem_l2,r0
loopend1
Rule L.G.4
At least one VLES is required between a MOVE-like instruction that reads the SR register and SA of any
short loop.
Example 7-75. SR Read to SA of Any Short Loop
doensh0 #$10
push sr
;not allowed
loopstart0
inc d0
loopend0