Found 312 Articles for Computer Architecture

There are four different methods to implement rename buffers such as using a merged architectural and rename register file, employing a separate name register file, or holding renamed values either in the ROB or in DRIS.In the first method, rename buffers are executed along with the architectural registers in a similar physical register file, known as the merged architectural and rename register file. The merged register file has to provide a large enough number of physical registers to implement both the architectural and rename registers. For instance, the Power1 provides 40 and the R10000 64 physical registers for renaming 32 ... Read More

The layout of the rename buffers establishes the actual framework for renaming. There are three basic components are the type and the number of the rename buffers and the basic mechanism which is used for accessing rename buffers as displayed in the figure.Type of rename buffersThe chosen type of rename buffers has the largest impact on renaming. It is definitive for the basic approach of the implementation and thus it determines where the intermediate results of the instruction are to be written into or read form. It can be designated as intermediate results which have already been generated but are ... Read More

Register renaming is a standard approach for eliminating false data dependencies, such as WAR and WAW dependencies, between register data. It was first suggested by Tjaden and Flynn in 1970.They intended to use register renaming for a definite set of instructions that compare more or less to the class of load instructions, although it does not use the phrase ‘renaming’. Keller (1975) introduced the designation ‘register renaming’ and interpreted it for all suitable instructions.Register Renaming presumes the three-operand instruction format. To illustrate this precondition, let us consider a two-operand instruction, sayad r1, r2with the interpretationr1←(r1)+(r2) In the two instruction format, ... Read More

Flip flops are an application of logic gates. A flip-flop circuit can stay in a binary state continually (as long as power is transferred to the circuit) before conducted by an input signal to switch states. S-R flip-flop represents SET-RESET flip-flops. The SET-RESET flip-flop includes two NOR gates and also two NAND gates. These flip-flops are also known as S-R Latch.The SR flip-flop has two inputs such as the ‘Set’ input and a ‘Reset’ input. The two outputs of SR flip-flop are the main output Q and its complement $\overline{Q}$.The diagram shows the circuit diagram of an SR flip-flop.The truth ... Read More

A latch is a device with particularly two stable states and these states are high-output and low-output. A latch has a feedback direction, to maintain the data. Latches can be memory devices and can save one bit of information. It is used to “latch onto” data and save it in the required area. One of the most generally used latches is the SR latch.SR LatchAn SR latch is an asynchronous device. An SR latch does not rely upon control signals but relies only on the state of the S and R inputs. An SR latch can be generated by interlinking ... Read More

A logic gate is an electronic device that creates logical decisions depends on the various combinations of digital signals accessible on its inputs. A digital logic gate can have greater than one input signal but has only one digital output signal. There are seven basic logic gates such as AND, OR, XOR, NOT, NAND, NOR, and XNOR.AND GateIt is a digital logic gate. It has an output that is frequently at logic level “0” and goes “HIGH” to a logic level “1” when all of its inputs are at logic level “1”. The output of AND gate returns “LOW” when ... Read More

Digital data is described, saved, and communicated as sets of binary digits which are known as bits. The set of bits is called binary code. Binary codes are used in devices as they enable computers to implement complex evaluations fastly and effectively.Classification of Binary CodesBinary codes can be defined as numbers and letters of the alphabet and some special characters and control services such as numeric or alphanumeric codes. Numeric codes can define numbers, whereas alphanumeric codes can define alphabetic letters and numerals. The binary codes are classified as demonstrated in the diagram.Numeric CodesNumeric codes can define numbers. There are ... Read More

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

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

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