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Questions tagged [digital-circuits]

Digital circuits use logic gates as the basic building block. A logic gate performs a logical operation on binary inputs and produces a single binary output. The Primary Logical operations are AND (conjunction), OR (disjunction) and NOT (negation).

Use this tag when discussing about the design, simulation and verification of digital circuits. To learn more about digital circuits visit:

Digital Electronics on Wikipedia

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Why is addition as fast as bit-wise operations in modern processors?

I know that bit-wise operations are so fast on modern processors, because they can operate on 32 or 64 bits on parallel, so bit-wise operations take only one clock cycle. However addition is a complex operation that consists of at least one and…
Teodor Dyakov
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Connection between NAND gates and Turing completeness

I know that NAND gates can be used to create circuits that implement every truth table, and modern computers are built up of NAND gates. What is the theoretical link between NAND gates and Turing completeness? It seems to me that NAND gate circuits…
bsm
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What is the exact difference between a latch & a flipflop?

From what I have understood : A Flip Flop is a clocked latch i.e. flip flop = latch + clock Latch continuously checks for inputs & changes the output whenever there is a change in input Flip Flop also continuously checks input, but changes the…
avi
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Trick/insight to I implement given boolean function with minimum numbers of given gate

I solved bunch of questions which give some function and then ask to implement it with minimum number of gates of specific type, each having specific number inputs. I was making mistakes in all those problems by not implementing given function with…
RajS
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Size of constant depth circuit for digital comparator?

Is a lower bound of $\Omega(n^2)$ known for the size of any constant depth circuit expressing a digital comparator for two $n$-bit numbers? Two $n$-bit binary numbers can be compared using a digital comparator circuit. The straightforward way to…
András Salamon
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Algorithms for logical synthesis of multiple output bits?

Karnaugh maps and the Quine–McCluskey algorithm can be good choices for coming up with fairly minimal logical expressions that match the requirements of a truth table. What if I have a situation where I have $M$ input bits and $N$ output bits…
Alan Wolfe
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In fast multiplier circuits, what is the difference between a Counter and a Compressor?

When working on fast parallel multiplier circuit designs, like Wallace tree multipliers or Dada tree multipliers I found many papers and books refer to different components used in the tree to reduce the partial products called things like (4:2)…
Alireza Tabatabaeian
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Analog circuits for neural networks?

Neural networks in machine learning are inherently a continuous model of computation. Yet we use digital logic circuits with floating point numbers to "emulate" this continuity. I am wondering: is there a possiblity to develop an analog-based ASIC…
user600670
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Is it possible to determine if C=A+B faster than adding A+B in logical circuits

With an adder circuit where A+B=C, I am trying to have a method to determine when C will be valid based on a change in A or B. I know that it is possible to just determine the longest the circuit would take, but is it possible to determine if the…
Eric Johnson
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Why is Computer Architecture in $2^n$ bits?

I have always wondered why is computer architecture in $2^n$ bits. We have 8 / 16 / 32 / 64-bit microprocessors or for that matter other parts of computer are also in power of 2 bits. The only logic I could understand from my reasoning is that…
SimpleGuy
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Do Karnaugh maps yield the simplest solution possible?

I'm learning to use a Karnaugh map, but I'm not sure if I obtained the simplest expression possible. Have a look at this example: Truth table (inputs are A B C; output is F): A B C | F 0 0 0 | 1 0 0 1 | 0 0 1 0 | 1 1 …
user23169
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Using analog values with Algebraic Normal Form?

Algebraic normal form (ANF) is a way of describing digital circuits made up of AND and XOR gates. The below is an example of an ANF expression which evaluates to true if two or more of it's three inputs are true ($\oplus$ being XOR, implicit…
Alan Wolfe
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Can bar codes theoretically be considered a type of digital memory?

Bar codes act just like any other device that contains data that you can read from. Can bar codes thus be considered a type of computer memory? I believe the principle is quite similar to the optical discs like CDs or DVDs. They work just like an SD…
yoyo_fun
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General Approach To Calculate Minimum Number Of Flip-Flops Required

In the previous two years of the GATE exams, a question has been asked for finding number of flip flop's for counting sequence $0−1−0−2−0−3$ in 2016 and $0−0−1−1−2−2−3−3−0−0$ in 2015. But still, the approach discussed in these questions hasn't…
Akhil Nadh PC
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Physical significance of Don't cares in Digital Logic design

In many Digital functions we come across don't care conditions where we use don't cares to minimize functions. What is the significance of these don't cares in real world scenario where we actually implement the functions using logic gates?
Ashutosh
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