Analog Devices ADSP-21261 SHARC Hardware Reference Manual page 109

In SISD mode (
tional, meaning that an operation performed on one processing element is
not duplicated on the other processing element. The SISD transfer uses a
source register and a destination register. Either register can be in either
element's data register file. For a summary of unidirectional transfers, see
the upper half of
condition for an instruction only tests in the PEx element but it applies to
the entire instruction.
In SIMD mode (
tional, meaning that an operation performed on one element is duplicated
in parallel on the other element. The instruction uses two source registers
(one from each element's register file) and two destination registers (one
from each element's register file). For a summary of bidirectional trans-
fers, see the lower half of
conditional explicit and implicit transfers are tested and executed sepa-
rately in PEx and PEy, respectively, as detailed in
Bidirectional register-to-register transfers in SIMD mode are allowed
between a data register and DAG, control, or status registers. When the
DAG, control, or status register is a source of the transfer, the destination
can be a data register. This SIMD transfer duplicates the contents of the
source register in a data register in both processing elements.

Careful programming is required when a DAG, control, or status
register is a destination of a transfer from a data register. If the des-
tination register has a complement (for example
), the SIMD transfer moves the contents of the explicit data
ASTATy
register into the explicit destination and moves the contents of the
implicit data register into the implicit destination (the comple-
ment). If the destination register has no complement (for example,
I0), only the explicit transfer occurs.
ADSP-2126x SHARC Processor Hardware Reference
bit=0), the register-to-register transfers are unidirec-
PEYEN
Table 2-17 on page
bit=1), the register-to-register transfers are bidirec-
PEYEN
Table 2-17. Note that in SIMD mode
Processing Elements
2-53. Note that in SISD mode a
Table
ASTATx
2-17.
and
2-51