Instruction Overview
15-4
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
Functional Description
The Dreg form of the Absolute Value instruction calculates the absolute
value of a 32-bit register and stores it into a 32-bit
dest_reg
. The accumu-
lator form of this instruction takes the absolute value of a 40-bit input
value in a register and produces a 40-bit result. Calculation is done
according to the following rules.
• If the input value is positive or zero, copy it unmodified to the
destination.
• If the input value is negative, subtract it from zero and store the
result in the destination. Saturation is automatically performed
with the instruction, so taking the absolute value of the larg-
est-magnitude negative number returns the largest-magnitude
positive number.
The
ABS
operation can also be performed on both Accumulators by a sin-
gle instruction.
Flags Affected
This instruction affects flags as follows.
•
AZ
is set if result is zero; cleared if nonzero. In the case of two
simultaneous operations,
AZ
represents the logical “OR” of the two.
•
AN
is cleared.
•
V
is set if the maximum negative value is saturated to the maximum
positive value and the
dest_reg
is a
Dreg
; cleared if no saturation.
•
VS
is set if
V
is set; unaffected otherwise.
•
AV0
is set if result overflows and the
dest_reg
is
A0
; cleared if no
overflow.
•
AV0S
is set if
AV0
is set; unaffected otherwise.
Содержание ADSP-BF53x Blackfin
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Страница 752: ...Examples 20 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 780: ...Product Identification Register 21 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 790: ...ADSP BF535 Flags A 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 800: ...Performance Monitor Registers B 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 994: ...Instructions Listed By Operation Code C 194 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 1042: ...Index I 40 ADSP BF53x BF56x Blackfin Processor Programming Reference...