ADSP-BF53x/BF56x Blackfin Processor Programming Reference
15-21
Arithmetic Operations
Both instruction versions align the dividend for the next iteration by left
shifting the dividend one bit to the left (without carry). This left shift
accomplishes the same function as aligning the divisor one bit to the right,
such as one would do in manual binary division.
The format of the quotient for any numeric representation can be deter-
mined by the format of the dividend and divisor. Let:
• NL represent the number of bits to the left of the binal point of the
dividend, and
• NR represent the number of bits to the right of the binal point of
the dividend (numerator);
• DL represent the number of bits to the left of the binal point of the
divisor, and
• DR represent the number of bits to the right of the binal point of
the divisor (denominator).
Then the quotient has NL – DL + 1 bits to the left of the binal point and
NR – DR – 1 bits to the right of the binal point. See the following
example.
Some format manipulation may be necessary to guarantee the validity of
the quotient. For example, if both operands are signed and fully fractional
(dividend in 1.31 format and divisor in 1.15 format), the result is fully
Dividend (numerator)
BBBB B .
NL bits
BBB BBBB BBBB BBBB BBBB BBBB BBBB
NR bits
Divisor (denominator)
BB .
DL bits
BB BBBB BBBB BBBB
DR bits
Quotient
BBBB .
BBBB BBBB BBBB
NL - DL +1
(5 - 2 + 1)
NR - DR - 1
(27 - 14 - 1)
4.12 format
Содержание ADSP-BF53x Blackfin
Страница 38: ...Conventions xxxviii ADSP BF53x BF56x Blackfin Processor Programming Reference...
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Страница 324: ...Instruction Overview 7 20 ADSP BF53x BF56x Blackfin Processor Programming Reference...
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Страница 742: ...Instruction Overview 19 54 ADSP BF53x BF56x Blackfin Processor Programming Reference...
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...