Analog Devices ADSP-BF53x Blackfin Reference page 321

, the value loaded into
Begin_Loop
from the current instruction to the first instruction in the loop. The user
is required to preserve half-word alignment by maintaining even values in
this register. The offset is interpreted as a one's-complement, unsigned
number, eliminating backwards loops.
, the value loaded into
End_Loop
tive offset from the current instruction to the last instruction of the loop.
When using the
cally address labels. The linker replaces the labels with offset values.
A loop counter register (
The register contains a 32-bit unsigned value, supporting as many as
4,294,967,294 trips through the loop. The loop is disabled (subsequent
executions of the loop code pass through without reiterating) when the
loop counter equals 0.
ADSP-BF535 Execution Note
The following information about instructions that are permissible as the
last instruction on a loop applies only to the ADSP-BF535 processor, not
to all ADSP-BF53x/BF56x processors.
The last instruction of the loop must not be any of the following
instructions.
•
Jump
•
Conditional Branch
•
Call
•
CSYNC
•
SSYNC
• Return (
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
LBn
instruction,
LSETUP
or
LC0 LC1
, , etc.)
RTS RTN
Program Flow Control
, is a 5-bit, PC-relative, even offset
LTn
, is an 11-bit, unsigned, even, PC-rela-
and
Begin_Loop
) counts the trips through the loop.
are typi-
End_Loop
7-17