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
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...