Texas Instruments TMS320C3x User Manual page 668

RPTB
Repeat Block
Example
13-210
RPTB 127h
Before Instruction
PC
RE
RS
ST
LUF
LV
UF
N
Z
V
C
Because the block-repeat modes modify the program counter, no
other instruction can modify the program counter at the same time.
The following two rules apply:
Rule 1: The last instruction in the block (or the only instruction in a
block of size 1) cannot be a B cond , BR, DB cond , CALL,
CALL cond , TRAP cond , RETI cond , RETS cond , IDLE, IDLE2,
RPTB, or RPTS. Example 7–3 on page 7-6 shows an
incorrectly placed standard branch.
Rule 2: None of the last four instructions at the bottom of the block
(or the only instruction in a block of size 1) can be a
B cond D, BRD, or DB cond D. Example 7–4 on page 7-7
shows an incorrectly placed delayed branch.
If either rule is violated, the PC will be undefined.
PC
0123
RE
0
RS
0
ST
0
LUF
0
LV
0
UF
0
N
0
Z
0
V
0
C
0
After Instruction
0124
127
124
100
0
0
0
0
0
0
0