ADSP-2126x SHARC Processor Hardware Reference
2-39
Processing Elements
5. PEx Multiplier
6. PEy Multiplier
7. PEx Shifter
8. PEy Shifter
The data register file in
lists register names of
R0
through
R15
within the PEx’s register file. When a program refers to these
registers as
R0
through
R15
, the computational units treat the contents of
these registers as fixed-point data. To perform floating-point computa-
tions, refer to these registers as
F0
through
F15
. For example, the following
instructions refer to the same registers, but direct the computational units
to perform different operations:
F0 = F1 * F2; /*floating-point multiply*/
R0 = R1 * R2; /*fixed-point multiply*/
The
F
and
R
prefixes on register names do not effect the 32-bit or 40-bit
data transfer; the naming convention only determines how the ALU, mul-
tiplier, and shifter treat the data.
To maintain compatibility with code written for previous SHARC
DSPs, the assembly syntax accommodates references to PEx data
registers and PEy data registers.
Code may only refer to the PEy data registers (
S0
through
S15
) for data
move instructions. The rules for using register names are:
•
R0
through
R15
and
F0
through
F15
always refer to PEx registers for
data move and computational instructions, whether the DSP is in
SISD or SIMD mode.
•
R0
through
R15
and
F0
through
F15
refer to both PEx and PEy reg-
ister for computational instructions in SIMD mode.
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 ...