Analog Devices ADSP-BF53x Blackfin Reference page 654

Instruction Overview
Parallel Issue
This instruction can be issued in parallel with specific other 16-bit
instructions. For details, see
Example
r4=a1.l+a1.h, r7=a0.l+a0.h ;
Also See
SAA (Quad 8-Bit Subtract-Absolute-Accumulate)
Special Applications
Use the Dual 16-Bit Accumulator Extraction with Addition instruction
for motion estimation algorithms in conjunction with the Quad 8-Bit
Subtract-Absolute-Accumulate instruction.
18-14 ADSP-BF53x/BF56x Blackfin Processor Programming Reference
"Issuing Parallel Instructions" on page 20-1.