ADSP-BF53x/BF56x Blackfin Processor Programming Reference
15-13
Arithmetic Operations
Add/Subtract – Prescale Up
General Form
dest_reg = src src_reg_1 (RND12)
dest_reg = src_reg_0 - src_reg_1 (RND12)
Syntax
Dreg_lo_hi = Dreg + Dreg (RND12) ; // (b)
Dreg_lo_hi = Dreg - Dreg (RND12) ; // (b)
Syntax Terminology
Dreg
:
R7–0
Dreg_lo_hi
:
R7–0.L
,
R7–0.H
Instruction Length
In the syntax, comment (b) identifies 32-bit instruction length.
Functional Description
The Add/Subtract – Prescale Up instruction combines two 32-bit values
to produce a 16-bit result as follows:
• Prescale up both input operand values by shifting them four places
to the left
• Add or subtract the operands, depending on the instruction version
used
• Round and saturate the upper 16 bits of the result
• Extract the upper 16 bits to the
dest_reg
Содержание ADSP-BF53x Blackfin
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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...