In many years, computer architecture has gone through evolutional instead of revolution changes supporting features are those that were demonstrated execution delivers.According to the figure we initiated with the Von Neumann architecture developed as a sequential machine implementing scalar information. Sequential devices enhanced from bit serial to word-parallel operations & from fixed point to floating-point operations. The Von Neumann architecture is moderate because of the sequential implementation of instructions in the program.Look ahead, Parallelism, and Pipelining − Lookahead methods were initiating to prefetch instructions to overlap I/E (instruction fetch/decode and execution) operations and to allow functional parallelism.Functional parallelism was provided ... Read More

It is widely observed that certain computer architecture classes and programming language classes correspond to one another. For example von Neumann architectures and imperative languages, or reduction architectures and functional languages. The corresponding architecture and language classes must have a common foundation or paradigm called a computational model.The computational model comprises the set of following three abstractions are as shown in the figure −The first abstraction identifies the basic items of computation. This is a specification of the items the computation refers to any kind of computations that can be performed on them.For instance, in the Von Neumann computational model, ... Read More

There are various elements of modern computers which are as follows −Computing Problems − It has been long identified that the theory of computer architecture is no greater limited to the mechanism of the bare machine hardware. A modern computer is an integrated system including machine hardware, an instruction set, system software, application programs, and user interfaces. These system elements are shown in the diagram.For scientific issues in science and technology, the solutions demand complex mathematical systems and endless integer or floating-point computations. For alphanumerical issues in business and government, the solutions demand detailed transactions, huge database management, and data ... Read More

There are few basic guidelines or design elements that distribute to categorize and differentiate buses.Bus TypesBus lines can be reported into two generic types are dedicated and multiplexed. A dedicated bus line is permanently authorized either to one function or a physical subgroup of computer components. A multiplexed bus line is assigned too many functions based on some parameters.Method of ArbitrationIn all but the simplest systems, more than one module can require control of the bus. Therefore only one unit at a time can strongly transfer over the bus, some method of arbitration is required. Various methods can be classified ... Read More

The hardware components of a computer are classified into five groups are Input unit, Central processing unit, Output Unit, Control Unit, Arithmetic & logical unit.Input unitInput units are used by the computer to read the information. The most frequently used input devices are keyboards, mouse, joysticks, trackballs, microphones, and so on. Whenever a key is clicked, the matching letter or digit is necessarily interpreted into its equivalent binary code and communicate over a cable to either the memory or the processor.Output unitThe output unit is the reverse of the input unit. When the processor sends the output to the output ... Read More

BCD adder refers to a 4-bit binary adder that can add two 4-bit words of BCD format. The output of the addition is a BCD-format 4-bit output word. It can descript the decimal sum of the addend and augend and a carry that is created in case this sum exceeds a decimal value of 9. Therefore, BCD adders can perform decimal addition.A BCD adder is a circuit that adds two BCD digits in parallel and makes a sum digit also in BCD. A BCD adder should contain the correction logic in its internal construction. To add 0110 to the binary ... Read More

Decimal arithmetic operations refer to a digital function that does decimal micro-operations. This function adds or subtracts decimal numbers by forming 9’s or 10’s complement of the subtrahend. This decimal arithmetic unit first accepts coded decimal numbers and then generates output in the binary form.Algorithms that are used for arithmetic operations with decimal data and binary data are alike. If the micro-operations symbol is interpreted correctly the same flowchart can be used for both multiplication and division.The decimal numbers in BCD are stored in groups of four bits in the computer registers. When performing decimal micro-operations, every 4-bit group represents ... Read More

A subtractor circuit is required to perform a subtraction operation on two decimal numbers. BCD subtraction is slightly different from BCD addition. Performing subtraction operation by taking the 9’s or 10’s complement of the subtrahend and adding it to the minuend is economical.It is not possible to obtain the 9’s complement by complementing every bit in the code because the BCD is not a self- complementing code. The 9’s complement has to be formed by a circuit that subtracts Notes every BCD number from 9.The 9’s complement of a decimal digit that is represented in BCD can be obtained by ... Read More

BCD adder refers to a 4-bit binary adder that can add two 4-bit words of BCD format. The output of the addition is a BCD-format 4-bit output word, which defines the decimal sum of the addend and augend and a carry that is created in case this sum exceeds a decimal value of 9. Therefore, BCD adders can implement decimal addition.Construction of BCD AdderSum of Binary DigitsSum of BCD DigitsKZ8Z4Z2Z1CS8S4S2S1Decimal00000000000000010000110001000010200011000113001000010040010100101500110001106001110011170100001000801001010019010101001010010111001111011001000012011011000113011101011014011111011115100001010016100011010117100101101018100111101119In this table, K is the carry. The subscripts below the letter Z define the weights. The weights, according to the table, are 8, 4, 2, and 1. These weights can ... Read More

The binary division is similar to division in decimals. The process involves successive comparison, shifting, and subtraction. The division of binary numbers is easy compared to the division of decimal numbers because the quotient is either 0 or 1. It is also not necessary to check the number of times the dividend (partial remainder) fits into the divisor.Divide OverflowIn a computer system, the division operation can lead to a quotient with an overflow because the registers cannot hold a number that exceeds the standard length. To understand this better, consider a system with a standard 5-bit register.One register is used ... Read More