lec_09_pipelining_2_spr08_s

lec_09_pipelining_2_spr08_s - Lecture 9 Pipelining...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
EE-449 Lec. 09 of 32 Lecture 9 – Pipelining EE-449 Computer Organization Spring 2008 Salvador Fallorina CSULA Pipelined Datapath & Control 04-28-08 1 Fallorina | CSULA
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EE-449 Lec. 09 of 32 Review: Pipeline Capabilities Pipelining takes advantage of parallelism by overlapping execution  of multiple instructions Pipelining can work since each execution step uses a different  functional unit, idle resources can be used by other instructions Pipelining doesn’t speedup execution of a single instruction, it  increases  throughput  of entire program. Entire programs run faster. Fallorina | CSULA 2
Image of page 2
EE-449 Lec. 09 of 32 Review: Pipelined Performance In the best case, a 5-stage pipeline will be  executing 5 instructions at a time. One  instruction will be finished on every cycle! Fallorina | CSULA 3 CPI Clock Cycle Time Single-cycle 1 high Multicycle                    >1 low Pipelined ~1 low
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EE-449 Lec. 09 of 32 Review: Pipelining Fallorina | CSULA 4 Pipeline Depth  = Number of pipeline stages = 5 At full pipeline, CPI =1 Sequence of instructions Short clock cycle time Time in clock cycles
Image of page 4
EE-449 Lec. 09 of 32 Review: Limits to Speedup Instructions forced to have need same number of stages to avoid  resource conflicts.  Time to “fill” and “drain” pipeline Pipeline overhead Hazards … Fallorina | CSULA 5 lw R-type sw beq, j
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EE-449 Lec. 09 of 32 Pipeline Hazards Hazards may prevent next instruction from executing  during its designated clock cycle (Resulting in undesired  pipeline stalls and “bubbles”) Structural Hazards Conflicts for resources at the same clock cycle These may be avoided through adding more functional units Data Hazards
Image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern