KSU CSIS 3510 - PIPELINE HAZARDS (10 pages)

Previewing pages 1, 2, 3 of 10 page document View the full content.
View Full Document

PIPELINE HAZARDS



Previewing pages 1, 2, 3 of actual document.

View the full content.
View Full Document
View Full Document

PIPELINE HAZARDS

34 views

Other


Pages:
10
School:
Kennesaw State University
Course:
Csis 3510 - Computer Org & Arch
Computer Org & Arch Documents

Unformatted text preview:

CSIS 3510 Computer Organization Architecture Dr Hoganson PIPELINE HAZARDS Hazards Up until now we have assumed an idealized pipeline Problems that can limit pipeline performance STRUCTURAL HAZARDS von Neuman characteristics multiple memory accesses for each instruction but only one bus to memory DATA DEPENDENCY HAZARDS Some instructions may need the results that are yet to be produced from the instruction s ahead of it in the pipeline but not yet complete CONTROL HAZARDS Jumps and branches interrupt the sequential flow of instructions cause pipeline to be flushed and reloaded said to be about 30 of all instructions Kennesaw State University E X C E E D I N G E X PE C TAT I O N S CSIS 3510 Computer Organization Architecture Dr Hoganson STRUCTURAL HAZARD Hazards In a 5 stage pipeline three of the five stages may require access to memory over the bus or access to cache IF memory access DE no access OF memory access EX no access RS memory access Causes the pipeline to STALL Reduces realizable performance Kennesaw State University E X C E E D I N G E X PE C TAT I O N S CSIS 3510 Computer Organization Architecture Dr Hoganson PIPELINE STALLS Hazards CYCLES subdivisions of system clock Instr 1 2 3 4 5 1 DE OF EX RS IF DE OF EX RS S S S S 2 3 4 5 IF 6 7 8 9 10 11 12 13 14 15 IF DE OF S Stall IF DE OF EX RS IF DE OF EX RS S S S S Note the pattern 2 instruction complete every six subdivided cycles SPEEDUP SERIAL over PARALLEL 2 5 6 10 6 1 667 Kennesaw State University E X C E E D I N G E X PE C TAT I O N S CSIS 3510 Computer Organization Architecture Dr Hoganson 1 2 3 4 FIX STRUCT HAZARD Hazards CACHE SEPARATE INSTRUCTION AND DATA CACHE WIDE WORD MEMORY MUTIPORT MEMORY Kennesaw State University E X C E E D I N G E X PE C TAT I O N S CSIS 3510 Computer Organization Architecture Dr Hoganson Enhanced von Neuman Hazards Allows fetch of two consecutive instructions at a time Frees the bus for operand fetches or result stores Implemented either as a wide word interface to the



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view PIPELINE HAZARDS and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view PIPELINE HAZARDS and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?