Found 690 Articles for Computer Science

What is Digital Electronics?

Ginni
Updated on 22-Jul-2021 13:49:56

3K+ Views

Digital electronics is an area of computer science. It manages with tools that can transmit out computer software. In digital electronics, we facilitate two-state or binary logic. There are two logic states including “0” (low) and “1” (high).A computer facilitates a binary number system for its services. Digital electronics defines the two binary numbers, including 1 and 0, using two voltage levels in a machine known as a logic gate. Frequently the two states can also be defined using Boolean logic functions, such as “true” or “false” states, or utilizing an “on” or “off” state.Logic gates are important elements of ... Read More

What are the Generations of Computer Systems?

Ginni
Updated on 22-Jul-2021 13:48:33

169 Views

In the electronic computer world, we measure technological growth by generation. A specific system belongs to a specific generation. Each generation denotes a significant change in computer design. The UNIVAC defines the first generation.The First Generation (1938-1953)The establishment of the first electronic analog computer in 1938 and the first electronic digital computer, ENIAC (Electronic Numerical Integrator and Computer), in 1946 denoted the starting of the first generation of computers. Electromechanical communication was used as switching tools in the 1940s and vacuum tubes were used in the 1950s.The Second Generation (1952-1963)Transistors were created in 1948. The first transistorized digital computer, TRADIC, ... Read More

What are the treatments of an empty reservation station?

Ginni
Updated on 22-Jul-2021 08:38:03

124 Views

When instruction arrives at an empty reservation station, the superscalar processor follows two different approaches as shown in the figure. The straightforward approach is to process is an instruction in the same way as with a partially filled reservation station. However, entering instructions have to stay for at least one cycle in the empty station before they are dispatched. The Nx586 is an example of a processor that treats an empty reservation station in this way.A more advanced approach for treating empty reservation stations is the use of bypasses. Here some additional circuitry permits instructions to bypass an empty station ... Read More

What are the schemes for checking the availability of operands?

Ginni
Updated on 22-Jul-2021 07:53:32

48 Views

The availability of operands has to be checked in two scenarios such as when the operands are fetched from the register file, a scheme is needed to check whether requested contents are available in the register file. A similar scheme is needed during instruction dispatch to check whether all the operands of the instructions held in the shelving buffers are available.The term scoreboard was introduced in connection with CDC 6600 (1964) to denote the complex circuitry used in this processor for controlling parallel operation. The figure shows the principle of scoreboarding.The scoreboard is a status register consisting of one-bit entries. ... Read More

What is Dispatch Rate?

Ginni
Updated on 22-Jul-2021 07:48:07

437 Views

Unlike individual reservation stations, a group or central reservation station, or a DRIS must be efficient in dispatching higher than one instruction in each cycle. In these cases, the design space needs an additional component that determines how many instructions can be dispatched from each of the reservation stations or the DRIS per cycle. This component is called dispatch rate.A shelving buffer must be capable of dispatching one instruction to any EU connected to it in each cycle. This is easier to achieve for group stations with two to three EUs than for a central station or a DRIS with ... Read More

What is Dispatch policy?

Ginni
Updated on 22-Jul-2021 07:40:01

359 Views

The dispatch policy specifies how instructions are selected for execution and how to dispatch blockages are handled. The dispatch policy can be considered as a scheduling policy consisting of the components specified as shown in the figure.Selection Rule − The selection rule specifies when instructions are considered executable. Let us take it for granted that renaming is employed and unresolved conditional transfer instructions are managed by speculative branch processing.Arbitration Rule − It can also need an arbitration rule for the case when more instructions are eligible for execution that can be disseminated in the next cycle. Most processors use a ... Read More

What are the types of Operands fetch Policies?

Ginni
Updated on 22-Jul-2021 07:26:28

559 Views

There are two types of operands fetch policies such as issue bound or dispatch bound. The issue-bound fetch policy defines that operands are fetched during instruction issues. In this method, shelving buffers influence instructions with their operand values, needing that the buffers be fully long to support space for all the source operands.The other basic operand fetch policy is the dispatch bound fetch policy, when operands are fetched during dispatching. In this case, shelving buffers contain short register identifiers instead of long operands.The issue bound fetch policyIn this case, while issuing the instructions, the referenced source register numbers are forwarded ... Read More

What are the layouts of Shelving Buffers?

Ginni
Updated on 22-Jul-2021 07:23:19

239 Views

Shelving buffers have three major aspects such as the type and capacity of the buffers used and the number of their read and write ports, as shown in the figure.Types of shelving buffersThere are two generic types of shelving buffers such as standalone shelving buffers and combined buffers which are used for shelving, renaming, and reordering as shown in the figure.In most cases shelving buffers are implemented as standalone shelving buffers, that is, buffers that are utilized particularly for shelving. This type of shelving buffer is usually designated reservation stations. In the superscalar processor, reservation stations are executed using three ... Read More

What is the design space of the Issue Rate?

Ginni
Updated on 20-Jul-2021 09:29:55

433 Views

A superscalar processor is created to produce an execution rate of more than one instruction per clock cycle for a single sequential program. Superscalar processor design generally defines a set of techniques that enable the central processing unit (CPU) of a computer to obtain a throughput of more than one instruction per cycle while implementing a single sequential program.The concept of the superscalar issue was first developed as early as 1970 (Tjaden and Flynn, 1970). It was later reformulated more precisely in the 1980s (Torng, 1982, Acosta et al, 1986).The function of superscalar processing is the superscalar instruction issue. A ... Read More

What are the Instruction issue policies of the superscalar processor?

Ginni
Updated on 20-Jul-2021 09:29:05

1K+ Views

The following methods used in instruction issue policies such as the scalar processors, superscalar processors, and the broad picture covering both. While considering the most frequently used issue policies, it can reduce the design space of instruction issues by ignoring less important aspects.First, for both scalar and superscalar processors, it can avoid issue order, because most processors employ an in-order issue. Moreover, it can discard issue alignment in the case of scalar and superscalar processors that make use of shelving.While considering instruction issue policies for scalar processors, it should be treated the three basic issue aspects such as whether to ... Read More

Advertisements