1. Multiprocessor - is a system having two or more processor and it executes more than one processes.Main feature of multiprocessor is to share main memory or other resources by all processors.In this one master CPU will control all other processors.The other processor maybe co-processor or input-output processors.
The basic characteristics of multiprocessor system are :
1)This system must have more than one processor.All these processor must have nearly identical processing
capabilities.
2)All these processor must have common shared memory.
3)Processors share all I/O devices or other resources.
4)The interaction among processor at program level must be defined precisely to have a good and efficient design of hardware for a multiprocessor system.
5)The system configuration can be enhanced at required increments at any point of time.
TYPES OF MULTIPROCESSOR
(A) Rightly Coupled
(B)Loosely Coupled
Rightly coupled shares common memory and each processor has its own local memory where loosely coupled does not have its own shared memory although each processor will have its own local memory.
The processor used in these types of system are specialized to handle different tasks.This system increases the overall reliability of system, that means if more than one processor fails, their load is being shared by other processor.
Different schemes used for interconnection of processors and memories are :
1.) Common Bus : This scheme will provide single bus for interconnection of processors and memory.Its is most effective and simple.
The failure of bus system results in total system failure.The performance of overall system is being limited by data transfer of bus.
2.)Multiple Bus Organisation :This system will provide two or more buses for interconnection of processor and memory.This scheme allows multiple data transfer simultaneously.This will increase reliability without increasing the cost too much.
3.)Crossbar Organisation : This scheme provides interconnection of n processor and n memory modules using switch elements.Switch element is having electronic circuit to provide desired path, it supports priority logic to resolve conflicts.
The hardware implementation is complex as compared to multiple bus organisation.
4.)Multistage Interconnection Network :
The basic characteristics of multiprocessor system are :
1)This system must have more than one processor.All these processor must have nearly identical processing
capabilities.
2)All these processor must have common shared memory.
3)Processors share all I/O devices or other resources.
4)The interaction among processor at program level must be defined precisely to have a good and efficient design of hardware for a multiprocessor system.
5)The system configuration can be enhanced at required increments at any point of time.
TYPES OF MULTIPROCESSOR
(A) Rightly Coupled
(B)Loosely Coupled
Rightly coupled shares common memory and each processor has its own local memory where loosely coupled does not have its own shared memory although each processor will have its own local memory.
The processor used in these types of system are specialized to handle different tasks.This system increases the overall reliability of system, that means if more than one processor fails, their load is being shared by other processor.
Different schemes used for interconnection of processors and memories are :
1.) Common Bus : This scheme will provide single bus for interconnection of processors and memory.Its is most effective and simple.
The failure of bus system results in total system failure.The performance of overall system is being limited by data transfer of bus.
2.)Multiple Bus Organisation :This system will provide two or more buses for interconnection of processor and memory.This scheme allows multiple data transfer simultaneously.This will increase reliability without increasing the cost too much.
3.)Crossbar Organisation : This scheme provides interconnection of n processor and n memory modules using switch elements.Switch element is having electronic circuit to provide desired path, it supports priority logic to resolve conflicts.
The hardware implementation is complex as compared to multiple bus organisation.
4.)Multistage Interconnection Network :
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