ADSP-2126x SHARC Processor Hardware Reference
3-23
Program Sequencer
The stall occurs during the decode phase of Instruction 3. Instruc-
tion 3 takes two cycles to complete decode.
Execution Stalls
The following events can cause an execution stall for the ADSP-2126x:
• One cycle on a Program Memory Data Access with instruction
cache miss
• Two cycles on non-delayed branches
• Two cycles on normal interrupts
• One to two cycles on short loops with small iterations
• n cycles on an
IDLE
instruction
• In a sequence of three instructions of the types shown below, the
processor may stall for one cycle:
Instruction 1: Compute instruction affecting flags such as
R2 = R3 - R4;
Instruction 2: Conditional instruction involving post-modify
addressing such as
IF EQ DM(I1,M1) = R15;
Instruction 3: Instruction such as
R0 = DM(I1,M2);
involving
post-modify addressing involving same
I
register. This last instruc-
tion stalls the processor for one cycle.
• Any read reference to a memory-mapped register located physically
within core (registers like
SYSCTL
, which are not situated in the
IOP) requires two cycles; therefore, the processor stalls for one
cycle.
Содержание ADSP-21261 SHARC
Страница 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Страница 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Страница 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Страница 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Страница 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...