• Digital-logic Laptops & Desktops Driver Download For Windows 10 Windows 7
• Digital-logic Laptops & Desktops Driver Download For Windows 10 64-bit
• Digital-logic Laptops & Desktops Driver Download For Windows 10 Laptop

• Access all your Box files directly from your desktop, without taking up much hard drive space. Box Drive is natively integrated into Mac Finder and Windows Explorer, making it easy to share and collaborate on files. Download Box Drive for Mac Download Box Drive for Windows (64 bit) Download Box Drive for Windows (32 bit).
• IMPORTANT NOTICE: Downloading the latest Driver releases helps resolve driver conflicts and improve your computer’s stability and performance.Updates are recommended for all Windows XP, Vista, Windows 7, Windows 8 and Windows 10 users.

Computers, and other digital systems, are designed using elementary electronic circuits called gates . In this article, Inverters, Or gates, and And gate s are introduced by logical statements justifying the term 'logic design.' Then, the design procedure is illustrated, and integrated circuits are discussed.

Digital Logic Ltd is a Serbian electronic company operating in the global market. Its business relies on 50 years’ experience in electronics and new technologies. In recent decades, our focus is on the NFC Reader solutions development. Our work is fulfilled with constant innovative ideas and engineering resourcefulness. Tips for better search results. Ensure correct spelling and spacing - Examples: 'paper jam' Use product model name: - Examples: laserjet pro p1102, DeskJet 2130 For HP products a product number. Examples: LG534UA For Samsung Print products, enter the M/C.

Gates

Gates are used to regulate electronic flow and to construct devices to process data, as well as to build memory devices. There are three fundamental gates—'And,' 'Or,' and 'Not'—as well as some 'hybrid' gates such as 'Nand' (Not-And) and 'Nor' (Not-Or).

Not

Consider the logical statement: 'The porch light is on (Z 1) when I am not home (A 0).' Z is the output; A is the input (I am home). A corresponding binary function, of one variable , which is also binary, is called 'Complement' or 'Not.' 'Not' is represented by 'Z ~A' and its behavior is:

The electronic implementation of Not is the inverter, a one-transistor current amplifier with one input and one output. A high (binary-1) input voltage, typically about 5 Volts, forces current into the amplifier's input. So, the amplifier draws current from its output, pulling its output voltage low (binary-0), typically, close to 0 Volts. A 1 or high input gives a 0 output (the complement of the input). Since a low input voltage provides no current to the amplifier's input, the amplifier draws no current from its output, causing a high voltage there. A low or 0 input gives a 1 output. The output is the opposite or complement (Not) of the input.

Or

Consider the logical statement: 'I wear a jacket (Z 1) if it is cold (A 1) or if it rains (B 1) or…' A corresponding binary function, of two or more binary variables, is called 'Or.' The behavior of 'Or' is tabulated for two and three variables:

One or the other or both (or 'all' three) of the inputs 'on' cause the output to be true. A Nor gate is like an inverter, but with N input terminals instead of one. A high input voltage on any of the inputs causes a low output voltage and a low voltage on all inputs causes a high output voltage. Since 'Nor' is the complement of 'Or,' 'Or' is implemented in electronics by a 'Nor-Not' tandem. 'Not-Nor' or 'OR.' But, 'Nor' has another application.

Consider a pair of two-input 'Nor' gates, and let the output of each gate be one of the other gate's inputs. Label the unused inputs as S and R, and assume both these inputs are low. A positive pulse on S causes the corresponding 'Nor' gate's output to go low. Since both inputs to the other gate are low, its output is high. The pair of gates remains in this state even after the pulse on S returns to 0. A positive pulse on R causes the output of R's 'Nor' gate to go low. Since both inputs to S's gate are low, its output is high. The pair of gates now remains in this opposite state even after the pulse on R returns to 0. This pair of cross-connected 'Nor' gates is called a 'Set-Reset Flip-Flop' and it is the basic binary storage element used throughout digital design. The memory element is a 1 if S (Set) is 1, 0 if S is 0, or, what is the same, R (Reset) is 1.

And

Consider the logical statement: 'I wear a hat (Z = 1) when it is cold (A = 1) and when it is raining (B = 1) and…' A corresponding binary functionof two or more binary variables is called 'And.' The behavior of 'And' is tabulated for two and three variables:

All inputs must be on for the output to be on.

Like a 'Nor' gate, a 'Nand gate' also has N input terminals and one output terminal. But, 'Nand' is more complicated than 'Nor,' because a low output voltage is caused by a high voltage on all the inputs, and the output voltage is high if any of the input voltages is low. 'And' is implemented in electronics by a 'Nand-Not' tandem. Again, 'Not-Nand,' or 'Not-Not-And,' hence, 'And.'

Design Example

Consider a binary circuit, with output X and three inputs. D and E are separate streams of binary data, and C is a control signal so that X D when C 0 and X E when C 1. That is, the output is equal to D when C is 0, and equals E when C is 1. C controls the output. This Binary Multiplexor's behavior is tabulated:

Compare the output to D's value when C is 0; compare the output to E's value when C is 1. In the first four rows of the table, X D because C 0. In the last four rows, X E because C 1. The device is called a multiplexor because it switches ('multiplexes') between the data streams D and E under the control of C. It is a 'binary multiplexor' because it switches between or 'multiplexes' among two devices, D and E. It takes turns servicing them under the control of C. Consider two approaches for implementing this function.

Canonic And-Or Implementation.

Any binary function can be implemented in three layers of logic: (1) a layer of inverters that provides the complement of each input if it is needed; (2) a layer with K different N-input 'And' gates where the circuit has N inputs and the circuit's output function has K one-points (one outputs); and (3) one K-input Or gate. Since the multiplexor's output function, X, has four one-points, the canonic 'And-Or'implementation has four 'And' gates, each with three inputs. The different 'And' gates' inputs are appropriately inverted so each gate identifies a different one-point (one in the output). For example, an 'And' gate whose inputs are ~C, D, and ~E has a 1-output when CDE 010. A four-input 'Or' gate, with an input from each 'And' gate, provides the circuit's output. This would be (~C,D,~E) (or) (~C,D,E) (or) (C,~D,E) (or) (C,D,E) for the four one-points (one outputs) given.

Based on the Logical Description.

We can design the multiplexor in an ad-hoc manner from its logical description. If the inputs to a two-input 'And' gate are ~C and D, this gate's output equals D when C equals 0, and is 0 when C equals 1. If the inputs to another two-input 'And' gate are C and E, this gate's output equals E when C equals 1, and equal 0 when C equals 0. The 'Or' of these two 'And' gates gives X. That is, the output is D (equal to D) when C is off (~C or C 0), the output equals E when C is on.

Obviously this second implementation, with only two two-input 'And'-gates and one two-input 'Or'-gate, is less expensive than the first. This is one of the issues in design. Cost, a complex issue, is illustrated next.

Integrated Circuits

Integration is the manufacture of more than one gate, an entire binary circuit, or even a whole system, on the same silicon chip. Transistorized gates and flip-flops were made in the 1950s from discrete resistors and transistors. Then, they were integrated onto a single chip, called a 'small-scale' integrated circuit (IC). Often, a chip's complexity is limited by the package's pin-outs. The '7400 series' of integrated circuits, introduced in the late 1960s, is still used today. If a part is popular, its per-chip overhead is small. Then, its price covers only the cost of materials and manufacturing— about $3 (in quantity). Allowing pins for common battery and ground, a 14-pin package has the following limits:

As chip manufacturers placed more logic circuits on a single chip of silicon, integration proceeded through three subsequent scales of fabrication. Simple binary functions are fabricated on a single chip with up to 100 transistors on a chip, in what has come to be called 'Medium Scale Integration.' For example, the Quad Set-Reset Flip-Flop is a useful digital integrated circuit (IC). But, when fitting four SR-FFs within the pin constraints of a 14-pin DIP (Dual In-Line Package), each SR-FF gets only three pins (14 2 (for battery and ground) 12; 12 / 4 (Quad) FF's 3 pins per SR flip-flop, 2 inputs, 1 output) and only one of each flip-flop's outputs is connected to a pin (the S or the R but not both).

More complicated digital circuits, such as binary counters and shift registers, are fabricated with many hundreds of transistors on a chip in 'LargeScale Integration.' Finally, modern digital circuits—like 16-and 32-bit CPUs and memory chips with vast amounts of binary storage—are fabricated with thousands of transistors on a chip in 'Very Large Scale Integration' (VLSI).

see also Boolean Algebra; Integrated Circuits; Transistors.

Richard A.Thompson

Bibliography

Booth, Taylor L. Digital Networks and Computer Systems.New York: Wiley, 1971.

Hill, Fredrick J., and G. R. Peterson. Introduction to Switching Theory and Logical Design.New York: Wiley, 1974.

A digital logic circuit is defined as the one in which voltages are assumed to be having a finite number of distinct value. Types of digital logic circuits are combinational logic circuits and sequential logic circuits. These are the basic circuits used in most of the digital electronic devices like computers, calculators, mobile phones.

Digital logic circuits are often known as switching circuits, because in digital circuits the voltage levels are assumed to be switched from one value to another value instantaneously. These circuits are termed as logic circuits, as their operation obeys a definite set of logic rules.

1. Combinational logic circuit

Combinational digital logic circuits are basically made up of digital logic gates like AND gate, OR gate, NOT gate and universal gates (NAND gate and NOR gate).

All these gates are combined together to form a complicated switching circuit. The logic gates are building blocks of combinational logic circuits. In a combinational logic circuit, the output at any instant of time depends only on present input at that particular instant of time and combinational circuits do not have any memory devices.

Encoders and Decoders are examples of combinational circuit. A decoder converts the binary coded data at its present input into a number of different output lines. Other examples of combinational switching circuits are half adder and full adder, encoder, decoder, multiplexer, de-multiplexer, code converter etc.

Combinational circuits are used in microprocessor and microcontroller for designing the hardware and software components of a computer.

Classification of combinational digital logic circuits

Combinational digital logic circuits are classified into three major parts – arithmetic or logical functions, data transmission and code converter.

The following chart will elaborate the further classifications of combinational digital logic circuit.

2. Sequential digital logic circuits

A Sequential digital logic circuit is different from combinational logic circuits. In sequential circuit the output of the logic device is not only dependent on the present inputs to the device, but also on past inputs.

In other words output of a sequential logic circuit depends on present input as well as present state of the circuit.

Unlike combinational circuits, the sequential circuits have memory devices in order to store the past outputs. In fact sequential digital logic circuits are nothing but combinational circuit with memory.These types of digital logic circuits are designed using finite state machine.

Examples of sequential logic circuits are counters, flip flops, constructed using digital logic gates and memory.

There are two inputs which are operated by combinational logic circuits in order to produce various outputs.

The output from the memory devices are fed to the combinational logic circuit. The internal inputs and outputs form part of the secondary devices.

Digital-logic Laptops & Desktops Driver Download For Windows 10 Windows 7

Secondary inputs devices are state variables produced by the storage elements, where as secondary outputs devices are excitations for the storage elements.

Types of sequential logic circuits Sequential digital circuits are classified into three major parts as Event driven, Clock drive and Pulse driven.

1. Clock Driven Circuits

These are synchronous digital logic circuit, where the output state transition takes place only when the input signal is applied along with clock pulses. Synchronous sequential circuit uses pulsed or clock inputs.

2. Event Driven Circuits

These are asynchronous digital logic circuits, where the output state transition takes place even if we don’t apply the input signal along with the clock pulses. Asynchronous circuit uses pulses of inputs instead of clock signal.

Output of sequential circuits can be pulsed output or level output.

Pulsed output: A pulsed output is an output that lasts for the duration of a particular input pulse but can be less in some cases. For the clocked sequential circuits, the output pulse is of the same duration as that of the clock pulse.

Level output: A level output refers to an output that changes state at the start of an input pulse or clock pulse and remains in that state until the next input or clock pulse.

Common Digital ICs used in digital logic circuits

Digital-logic Laptops & Desktops Driver Download For Windows 10 64-bit

Given below is a tabular form of the summary of CMOS and TTL digital ICs used in most of the digital circuits.

We hope our article has been informative in a simple way and the readers are now able to get a clear understanding of the types of digital logic circuits. Here is a simple question for any interested reader- What are pulse driven sequential logic circuits and give an example. If you have any queries on this topic or on the electrical and electronic projects Kindly give your answers in the comment section below.

Photo credits:

Combinational Logic Circuits by igem
Classification of combinational logic circuits by electronics-tutorials
Sequential logic circuit by electronics-tutorials
Sequential Circuit: J/K Flip-flop by cloudfront

Digital-logic Laptops & Desktops Driver Download For Windows 10 Laptop