ADSP-BF53x/BF56x Blackfin Processor Programming Reference
15-17
Arithmetic Operations
on page 1-21
for more details. Unless circular buffering is desired,
disable it prior to issuing this instruction by clearing the Length
Register (
Lreg
) corresponding to the
Ireg
used in this instruction.
Example: If you use
I2
to increment your address pointer, first
clear
L2
to disable circular buffering. Failure to explicitly clear
Lreg
beforehand can result in unexpected
Ireg
values.
The circular address buffer registers (Index, Length, and Base) are
not initialized automatically by Reset. Traditionally, user software
clears all the circular address buffer registers during boot-up to dis-
able circular buffering, then initializes them later, if needed.
Flags Affected
D-register versions of this instruction set flags as follows.
•
AZ
is set if result is zero; cleared if nonzero.
•
AN
is set if result is negative; cleared if non-negative.
•
AC0
is set if the operation generates a carry; cleared if no carry.
•
V
is set if result overflows; cleared if no overflow.
•
VS
is set if
V
is set; unaffected otherwise.
• All other flags are unaffected.
L
The ADSP-BF535 processor has fewer
ASTAT
flags and some flags
operate differently than subsequent Blackfin family products. For
more information on the ADSP-BF535 status flags, see
Table A-1
on page A-3
.
The P-register and I-register versions of this instruction do not affect any
flags.
Summary of Contents for ADSP-BF53x Blackfin
Page 38: ...Conventions xxxviii ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 134: ...System Reset and Powerup 3 18 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 324: ...Instruction Overview 7 20 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 486: ...Instruction Overview 13 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 512: ...Instruction Overview 14 26 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 604: ...Instruction Overview 15 92 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 688: ...Instruction Overview 18 48 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 742: ...Instruction Overview 19 54 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 752: ...Examples 20 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 790: ...ADSP BF535 Flags A 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 800: ...Performance Monitor Registers B 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 1042: ...Index I 40 ADSP BF53x BF56x Blackfin Processor Programming Reference...