Analog Devices ADSP-BF53x Blackfin Reference page 397

Functional Description
The Move Register Half instruction copies 16 bits from a source register
into half of a 32-bit register. The instruction does not affect the unspeci-
fied half of the destination register. It supports only D-registers and the
Accumulator.
One version of the instruction simply copies the 16 bits (saturated at 16
bits) of the Accumulator into a data half-register. This syntax supports
truncation and rounding beyond a simple Move Register Half instruction.
The fraction version of this instruction (the default option) transfers the
Accumulator result to the destination register according to the diagrams in
Figure 9-1. Accumulator
destination D-register.
tination D-register.
A0
Destination Register XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX
A1 0000 0000
Destination Register XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX
Figure 9-1. Result to Destination Register (Default Option)
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
contents transfer to the lower half of the
A0.H
contents transfer to the upper half of the des-
A1.H
A0.X A0.H
0000 0000 XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX
A0.X A0.H
XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX
Move
A0.L
A0.L
9-17