Static Programming Rules

7.5.8 Loop LA Rules

Rule L.L.1

The following instructions are not allowed at LA-1 or LA of a long loop:

COF instructions

STOP and WAIT

DI

DEBUG

Example 7-54. Instructions at the End of Long Loops

move.w #count2,d6 dosetup0 label2 doen0 d6

move.w #1,d1 move.w #2,d2 move.w #3,d3 move.w #4,d4

loopstart0

label2 inc d1 inc d2 inc d3 inc d4

wait;not allowed loopend0

Rule L.L.2

A DOENn or MOVE-like instruction that writes a LCn register is not allowed at LA-2, LA-1, or LA of the same long loop n.

Example 7-55. LCn Write at the End of Long Loop n

doen1 #5

;not allowed

move.w d3,(r1)+

 

loopend1

 

SC140 DSP Core Reference Manual

7-31

Page 281
Image 281
Freescale Semiconductor SC140 Loop LA Rules, Rule L.L.1, Rule L.L.2, Example 7-54. Instructions at the End of Long Loops