CSC/ECE 506 Fall 2007/wiki3 8 a1: Difference between revisions
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== Background == | == Background == | ||
The protocols discussed here were created to allow coherence to be maintained on a system that has no global bus system that allows snooping to take place, and, has distributed memory that is physically separated. These systems usually consist of PCM (Processor-Control-Memory) nodes connected by a network; the systems also have network assists to allow communication to take place. | The protocols discussed here were created to allow cache coherence to be maintained on a system that has no global bus system that allows snooping to take place, and, has distributed memory that is physically separated. These systems usually consist of PCM (Processor-Control-Memory) nodes connected by a network; the systems also have network assists to allow communication to take place. | ||
For a system to be coherent it must: | For a system to be coherent it must: | ||
| Line 6: | Line 6: | ||
#Manage the coherence protocol | #Manage the coherence protocol | ||
#*Determine when the coherence protocol should be used | #*Determine when the coherence protocol should be used | ||
#* | #*Find information on the current cache block in other caches | ||
#*Find out where other copies of the current cache block are located | |||
#*Communicate with the other copies | |||
== SSCI (Simple Scalable Coherence Interface) protocol == | == SSCI (Simple Scalable Coherence Interface) protocol == | ||
== IEEE SCI (Scalable | == IEEE SCI (Scalable Coherence Interface) protocol == | ||
== SSCI and IEE SCI Protocol Similarities == | == SSCI and IEE SCI Protocol Similarities == | ||
Revision as of 00:54, 17 October 2007
Background
The protocols discussed here were created to allow cache coherence to be maintained on a system that has no global bus system that allows snooping to take place, and, has distributed memory that is physically separated. These systems usually consist of PCM (Processor-Control-Memory) nodes connected by a network; the systems also have network assists to allow communication to take place.
For a system to be coherent it must:
- Provide a state machine
- Manage the coherence protocol
- Determine when the coherence protocol should be used
- Find information on the current cache block in other caches
- Find out where other copies of the current cache block are located
- Communicate with the other copies
SSCI (Simple Scalable Coherence Interface) protocol
IEEE SCI (Scalable Coherence Interface) protocol
SSCI and IEE SCI Protocol Similarities
IEE SCI Protocol Additional States
Links
IEEE SCI Standard Abstract and Content Summary -
http://standards.ieee.org/reading/ieee/std_public/description/busarch/1596-1992_desc.html
IEEE SCI on ieexplore -
http://ieeexplore.ieee.org/iel5/285/3365/00113656.pdf?tp=&arnumber=113656&isnumber=3365