The basic element of a multistage network is a two-input, two-output interchange switch. As displayed in the figure, the 2 X 2 switch has two inputs labeled A and B, and two outputs labeled 0 and 1.There are control signals related to the switch. The control signals start interconnection between the input and output terminals. The switch can join input A to either of the outputs. Terminal B of the switch facilitates similarly. The switch can also arbitrate between conflicting requests.In case, inputs A and B request the same output terminals, it is possible that only one of the inputs ... Read More

The crossbar switch organization includes various crosspoints that are located at intersections between processor buses and memory module directions. The diagram shows a crossbar switch interconnection between four CPUs and four memory modules.The tiny square in each crosspoint is a switch that decides the direction from a processor to a memory module. Every switch point has to control logic to set up the transmission direction between a processor and memory.It determines the address that is located in the bus to decide whether its specific module is being addressed. It can also resolve several requests for an approach to the equal ... Read More

Multiport memory is a memory that helps in providing more than one access port to separate processors or to separate parts of one processor. A bus can be used to achieve this kind of access.This mechanism applies to interconnected computers too. A multiport memory system uses separate buses between each CPU and each memory module.Each processor bus is linked to each memory module. A processor bus includes three components as an address, information, and control lines. These components are required to connect with memory. The memory module has four ports and each port includes one of the buses.A module should ... Read More

In the time-shared common bus, there are numerous processors linked by a common direction to the memory unit in a common-bus multiprocessor system. The figure shows the organization of time-shared common buses for five processors.There is only one processor that can interact with the memory of another processor. The processor that is in control of the bus at the time implements transfer operations. Any processor that needs to start a transfer should first check the availability condition of the bus.During the bus is available, the processor can start a connection with the destination unit to introduce the transfer. A command ... Read More

Shared Memory MultiprocessorsIn shared-memory multiprocessors, numerous processors are accessing one or more shared memory modules. The processors may be physically connected to the memory modules in many ways, but logically every processor is connected to every memory module.One of the major characteristics of shared memory multiprocessors is that all processors have equally direct access to one large memory address space. The limitation of shared memory multiprocessors is memory access latency.The figure shows shared-memory multiprocessors.Shared memory multiprocessors have a major benefit over other multiprocessors since all the processors sent a similar view of the memory.These processors are also termed Uniform Memory ... Read More

A multiprocessor is a single computer that has multiple processors. It is possible that the processors in the multiprocessor system can communicate and cooperate at various levels of solving a given problem. The communications between the processors take place by sending messages from one processor to another, or by sharing a common memory.Characteristics of MultiprocessorThere are the major characteristics of multiprocessors are as follows −Parallel Computing − This involves the simultaneous application of multiple processors. These processors are developed using a single architecture to execute a common task. In general, processors are identical and they work together in such a ... Read More

A multiprocessor is a data processing system that can execute more than one program or more than one arithmetic operation simultaneously. It is also known as a multiprocessing system. Multiprocessor uses with more than one processor and is similar to multiprogramming that allows multiple threads to be used for a single procedure.The term ‘multiprocessor’ can also be used to describe several separate computers running together. It is also referred to as clustering. A system is called a multiprocessor system only if it includes two or more elements that can implement instructions independently.A multiprocessor system employs a distributed approach. In the ... Read More

A virtual memory organization is a consolidation of hardware and software systems. It can make efficient utilization of memory space all the software operations are handled by the memory management software.The hardware mapping system and the memory management software together form the structure of virtual memory.When the program implementation starts, one or more pages are transferred into the main memory and the page table is set to denote their location. The program is implemented from the main memory just before a reference is created for a page that is not in memory. This event is defined as a page fault.When ... Read More

The table execution of the address mapping is interpreted if the data in the address space and the memory space are each split into a collection of fixed sizes. The physical memory is broken down into sets of similar size known as blocks, which can range from 64 to 4096 words each. The term page defines a set of address spaces of a similar size.Example − Suppose a page or block consists of 1K words, then address space can be divided into 1024 pages and main memory can be divided into 32 blocks.Even though both a page and a block ... Read More

Addresses that are used by programmers are known as virtual addresses, and the set of such addresses is known as the address space. Space or spot where the address is saved in the main memory is referred to as location or physical address and the set of such locations is known as the memory space.Therefore, the address space is the set of addresses generated by programs as they reference instructions and data. The memory space holds the actual main memory locations that are directly addressable for processing.Example − Consider, main-memory having a capacity of 32K words (K = 1024). 15 ... Read More