
Multifunction Computations
2-42
ADSP-2126x SHARC Processor Hardware Reference
way as the single function computations, except that in the dual add/sub-
tract computation, the ALU flags from the two operations are ORed
together.
To work with the available data paths, the computational units constrain
which data registers hold the four input operands for multifunction com-
putations. These constraints limit which registers may hold the X input
and Y input for the ALU and multiplier.
shows a computational unit and indicates which registers may
serve as X inputs and Y inputs for the ALU and multiplier. For example,
the X input to the ALU can only be
R8
,
R9
,
R10
or
R11
. Note that the
shifter is gray in
to indicate no shifter multifunction
operations.
, and
list the multifunc-
tion computations. For more information on assembly language syntax,
see
SHARC Processor Programming Reference
. In these tables, note the
meaning of the following symbols:
•
Rm
,
Ra
,
Rs
,
Rx
,
Ry
indicate any register file location; fixed-point
•
Fm
,
Fa
,
Fs
,
Fx
,
Fy
indicate any register file location; floating-point
•
R3–0
indicates data file registers
R3
,
R2
,
R1
, or
R0
, and
F3–0
indi-
cates data file registers
F3
,
F2
,
F1
, or
F0
•
R7–4
indicates data file registers
R7
,
R6
,
R5
, or
R4
, and
F7–4
indi-
cates data file registers
F7
,
F6
,
F5
, or
F4
•
R11–8
indicates data file registers
R11
,
R10
,
R9
, or
R8
, and
F11–8
indicates data file registers
F11
,
F10
,
F9
, or
F8
•
R15–12
indicates data file registers
R15
,
R14
,
R13
, or
R12
, and
F15–12
indicates data file registers
F15
,
F14
,
F13
, or
F12
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 ...