Setting DAG Modes
4-6
ADSP-2126x SHARC Processor Hardware Reference
register load operation on both processing elements with register load
broadcasting enabled. In
, note that
Rx
and
Sx
are complemen-
tary data registers. Note also that the letters a and b (as in Ma or Mb)
indicate numbers for modify registers in DAG1 and DAG2. The letter a
indicates a DAG1 register and can be replaced with 0 through 7. The let-
ter b indicates a DAG2 register and can be replaced with 8 through 15.
The
PEYEN
bit (SISD/SIMD mode select) does not influence broad-
cast operations. Broadcast loading is particularly useful in SIMD
applications where the algorithm needs identical data loaded into
each processing element. For more information on SIMD mode (in
particular, a list of complementary data registers), see
(Computational) Operations” on page 2-50
.
Alternate (Secondary) DAG Registers
To facilitate fast context switching, the DSP includes alternate register sets
for all DAG registers. Bits in the
MODE1
register control when alternate reg-
isters become accessible. While inaccessible, the contents of alternate
registers are not affected by DSP operations. Note that there is a maxi-
mum one cycle latency between writing to
MODE1
and being able to access
an alternate register set. The alternate register sets for the DAGs are
described in this section. For more information on alternate data and
results registers, see
“Alternate (Secondary) Data Registers” on page 2-40
.
Table 4-1. Dual Processing Element Register Load Broadcasts
Instruction syntax
Rx = DM(I1,Ma); {Syntax #1}
Rx = PM(I9,Mb); {Syntax #2}
Rx = DM(I1,Ma), Rx = PM(I9,Mb); {Syntax #3}
PEx explicit operations
Rx = DM(I1,Ma); {Explicit #1}
Rx = PM(I9,Mb); {Explicit #2}
Rx = DM(I1,Ma), Rx = PM(I9,Mb); {Explicit #3}
PEy implicit operations
Sx = DM(I1,Ma); {Implicit #1}
Sx = PM(I9,Mb); {Implicit #2}
Sx = DM(I1,Ma), Sx = PM(I9,Mb); {Implicit #3}
Summary of Contents for ADSP-21261 SHARC
Page 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Page 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Page 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Page 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Page 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Page 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Page 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Page 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Page 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Page 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Page 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Page 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...