Core Registers
A-6
ADSP-2126x SHARC Processor Hardware Reference
11
NESTM
Nesting Multiple Interrupts Enable.
Enables (nest if set, = 1) or dis-
ables (no nesting if cleared, = 0) interrupt nesting in the interrupt
controller. When interrupt nesting is disabled, a higher priority inter-
rupt can not interrupt a lower priority interrupt’s service routine.
Other interrupts are latched as they occur, but the processor processes
them after the active routine finishes. When interrupt nesting is
enabled, a higher priority interrupt can interrupt a lower priority
interrupt’s service routine. Lower interrupts are latched as they occur,
but the processor processes them after the nested routines finish.
12
IRPTEN
Global Interrupt Enable.
Enables (if set, = 1) or disables (if cleared,
= 0) all maskable interrupts.
13
ALUSAT
ALU Saturation Select.
Selects whether the computational units satu-
rate results on positive or negative fixed–point overflows (if 1) or
return unsaturated results (if 0).
14
SSE
Fixed–Point Sign Extension Select.
Selects whether the computa-
tional units sign-extend short-word, 16-bit data (if 1) or zero-fill the
upper 32 bits (if 0).
15
TRUNC
Truncation Rounding Mode Select.
Selects whether the computa-
tional units round results with round-to-zero (if 1) or round-to-near-
est (if 0).
16
RND32
Rounding For 32-Bit Floating-Point Data Select.
Selects whether the
computational units round floating-point data to 32 bits (if 1) or
round to 40 bits (if 0).
20–17
Reserved
21
PEYEN
Processor Element Y Enable.
Enables computations in PEy—SIMD
mode—(if 1) or disables PEy—SISD mode—(if 0).
When set, Processing Element Y (computation units and register files)
accepts instruction dispatches. When cleared, Processing
Element Y goes into a low power mode.
Note if SIMD Mode disabled you can load data to the secondary reg-
isters e.g. s0=dm(i0,m0); only computation does not work.
Table A-2. Mode Control 1 Register (MODE1) Bit Descriptions (Cont’d)
Bit
Name
Description
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 ...