ADSP-2126x SHARC Processor Hardware Reference
3-1
3 PROGRAM SEQUENCER
The DSP’s program sequencer controls program flow by constantly pro-
viding the address of the next instruction to be fetched for execution.
Program flow in the DSP is mostly linear, with the processor executing
instructions sequentially. This linear flow varies occasionally when the
program branches due to nonsequential program structures, such as those
shown below. Nonsequential structures direct the DSP to execute an
instruction that is not at the next sequential address following the current
instruction. These structures include:
•
Loops.
One sequence of instructions executes multiple times with
zero overhead.
•
Subroutines.
The traditional
CALL
/
RETURN
structure where the pro-
cessor temporarily breaks sequential flow to execute instructions
from another part of program memory.
•
Jumps.
Program flow is permanently transferred to another part of
program memory.
•
Interrupts.
A runtime event (generally not an instruction) triggers
the program sequencer to branch to interrupt-handling
subroutines.
•
Idle.
An instruction that causes the core to stop executing further
instructions and hold its current state until an interrupt occurs.
Then, after the processor services the interrupt, the sequencer
resumes normal program execution.
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 ...