# DIGITAL LOGIC PDF

If you need more information there are many books in the library that cover digital logic. Up until now the labs have dealt with electricity in its analog form where. Digital logic is the manipulation of binary values through printed circuit board technology that uses circuits and logic gates to construct the implementation of. Introduction. Digital, or boolean, logic is the fundamental concept underpinning all modern computer systems. Put simply, it's the system of rules that allow us to  ‎Introduction · ‎Combinational Logic · ‎Sequential Logic.

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## What is Digital Logic?

They learn how simple digital logic of ones and zeros can be used to store information on computers, including documents, images, sounds, and movies.

Coursework trains students to input their algorithms into computer-assisted design or CAD software digital logic create schematics of logic gates and circuits for a wide variety of electronic devices.

A collection of 3 bits has 8 possible states,,and In general, a collection of n bits has 2n states. For example, a byte contains eight bits, and is built by grouping eight binary bits into digital logic object, as shown in Figure 4.

Another name for a collection of eight bits is octet octo is Latin and Greek meaning 8.

Information can take many forms, e. What the bits mean depends on how the information is organized digital logic more importantly how it is used. This figure shows one byte in the state representing the binary digital logic Again, the output voltage 3.

### Logic gate

A byte is comprised of 8 bits, in this case representing the binary number What these 8 bits mean depends on how the computer software chooses digital logic interpret them. This technique also works for two digital logic trivialfour variables shown belowand even more though this gets complicated and will not be described here.

A typical four variable map and its groupings are shown here. Prove it to yourself.

Truth Table and Karnaugh map Alternate solution others possible Sequential Logic The digital logic described thus far is called combinatorial logic because the output depends solely upon the presently existing combination of the inputs; past values of the inputs are not important.

Sequential logic deals with the issue of time dependence and can get much more complicated than digital logic logic -- much in the same way that differential equations are more difficult than algebraic equations. The outputs of all Digital logic gates are low if any of the inputs digital logic high.

The symbol is an OR gate with a small circle on the output. An encircled plus sign is used to show the EOR operation. Electronic logic gates differ significantly from their relay-and-switch equivalents. They are much faster, consume much less power, and are much smaller all by a factor of a million or more in most cases.

Also, there is a fundamental structural difference. The switch circuit creates a continuous metallic path for current to flow in either direction between its input and its output. The semiconductor logic gate, on the other hand, acts as a high- gain voltage amplifierwhich sinks a tiny current at its input and produces a low-impedance voltage at its output.

It is not possible for current to flow between the output and the input of a semiconductor logic gate. Bad designs have intermittent problems such as "glitches", vanishingly fast pulses that may trigger some logic but not others, " runt pulses " that do not reach valid "threshold" voltages, or unexpected "undecoded" combinations of logic states.

Additionally, where clocked digital systems interface to analog systems or systems that are driven from a different clock, the digital system can be subject to metastability where a change to the input violates the set-up time for a digital input latch.

This situation will self-resolve, but will take a random time, and while it persists can result in invalid signals being propagated digital logic the digital system for a short time. Since digital circuits are made from analog components, digital circuits calculate more slowly than low-precision analog circuits that use a similar amount of space and power.

However, the digital circuit will calculate more repeatably, because of its high noise immunity. On the other hand, in the high-precision domain for example, where 14 or more bits of precision are neededanalog circuits require much more power and area digital logic digital equivalents.

Automated design tools[ edit ] To save costly engineering effort, much of the effort of designing large logic machines has been automated.

The computer programs are called " electronic design automation tools" or just "EDA. The most common example of this kind of digital logic is the Espresso heuristic logic minimizer.