ADSP-BF53x/BF56x Blackfin Processor Programming Reference
14-11
Shift/Rotate Operations
Options
Option (S) invokes saturation of the result.
In the default case–without the saturation option–numbers can be
left-shifted so far that all the sign bits overflow and are lost. However,
when the saturation option is enabled, a left shift that would otherwise
shift nonsign bits off the left-hand side saturates to the maximum positive
or negative value instead. Consequently, with saturation enabled, the
result always keeps the same sign as the original number.
See
“Saturation” on page 1-17
for a description of saturation behavior.
Flags Affected
The versions of this instruction that send results to a
Dreg
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.
•
V
is set if result overflows; cleared if no overflow.
•
VS
is set if
V
is set; unaffected otherwise.
• All other flags are unaffected.
The versions of this instruction that send results to an Accumulator
A0
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.
•
AV0
is set if result is zero; cleared if nonzero.
•
AV0S
is set if
AV0
is set; unaffected otherwise.
• All other flags are unaffected.
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...