Questions tagged [nand]
Use this tag when referring to any circuit that uses NAND gate / NAND logic, or for asking questions relating to NAND gates.
137
questions
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55 views
Confused about positive edge-triggered D flip-flop
I'm reading the book Digital Design and Computer Architecture. I don't understand this passage:
This is a D flip-flop with active low asynchronous set and
reset inputs. If S' and R' are both 1, the ...
-1
votes
0answers
36 views
Is there a diagram or a graph that describes the regions of both transistors in the TTL circuit?
Can someone describe in what regions both transistors will be in this graph?
1
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0answers
67 views
Memory Mapping Table
I am a begginer in the field of microcomputers and their architecture and recently I got an assignment with the following instructions:
With the use of the mapping table find out which adresses in ...
0
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0answers
35 views
Is there some way to differentiate between NAND and other flash types on a PCB?
Modern devices (smartphone, notebooks) often use some kind of flash for data storage. Depending on the vendor this can be emmc, ufs, nvme and maybe even plain old NAND.
The problem is you can't really ...
2
votes
1answer
62 views
What does the "source-like" symbol mean in the first NMOS of the CMOS NAND gate?
I would assume that it means the source is not left floating if Q4 is off
(boot-strapping ?).
5
votes
5answers
991 views
Boolean Logic - Realization with using only 4 NAND gates
I am currently preparing the next semester of my program at university and I am stuck at a question of the "Digital Circuits" class.
Here is the task:
[...] pump P1 runs when the fill-level ...
0
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2answers
84 views
Is a NAND flash chip better for power saving purposes as a micro SD card?
I know, they are technically the same, but from what I read, NAND flash chips can be controlled better like putting it into standby and waking it up in the matter of a few nanoseconds, which could be ...
0
votes
2answers
82 views
Generating random bits using two oscillators and a D Flip-Flop
I'm an electronic musician and computer science student I have been tinkering a lot lately with Arduino and analog ways of sound synthesis. Mainly I've been using 4093 ICs (NAND gates) to make ...
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2answers
64 views
SR Flip Flop Latches
Which gate, NAND or NOR is a better choice for making SR Flip Flop latch? Please, provide the reason too.
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35 views
Method to realize any function with 2 input NAND/NOR gate
I'm preparing for a competitive exam where often these type of questions are asked
Find the minimum number of 2 input NAND gates required to implement the function F(A, B, C, D) = AB + ACD + BC’ ...
0
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1answer
182 views
How to find NAND logic with the help of full adder?
Obtain a NAND logic diagram of a single full-adder from the Boolean
functions:
C= xy+xz+yz
S= C’(x+y+z)+xyz
I didn't understand the question. What do I have to do here? Do I have to simplify the ...
0
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0answers
51 views
How can I make this symmetric non-overlapping clock using digital Logic components?
How can I make a (dead-time) non overlapping symmetric clock like this with digital components such as inverters and NAND gates with 7 separate phases?
The first photo is doctored to show what I want ...
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2answers
1k views
Why is the PMOS in NAND gate in Parallel and NMOS Series?
Why is the PMOS in Parallel, and the NMOS is in series?
0
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1answer
64 views
What NAND gate chips should I use to create a simple computer
I have been reading the bool 'The Elements of Computing Systems' and I have designed a circuit for the computer that will use 1232 NAND gates, which assuming that there are 4 on a chip, is 308 chips. ...
2
votes
2answers
412 views
Multiple Switch Equation to NAND Only equation
I'm trying to convert a regular Boolean equation that has multiple inputs into a NAND only equation. My guess is that I'm supposed to convert using DeMorgan's law, but I'm not entirely sure how to do ...
0
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0answers
66 views
Nand gate is not working
I am trying to use a nand gate from a 4093BE chip with a digital sensor which is supposed to output 5 V when an obstruction is detected and 0 when not. I am setting both inputs of gate to the output ...
1
vote
3answers
86 views
Implement \$AB \overline{C}+\overline{BC}\$ using only a maximum of three 3-input NAND gates only
I need help with this question, I am lost.
0
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1answer
46 views
Does a secure erase on a SSD with lots of free space cost less P/E cycles than an SSD that's almost full?
Doing an ATA Secure Erase on an SSD should reset all of the cells to factory condition, which results in a program/erase cycle on cells at least in blocks that contain data.
On self-encrypting drives,...
1
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0answers
41 views
Realizing an XOR expression using NAND gates [duplicate]
I've been trying really hard to understand the construction of a logical circuit using only NAND while also trying to minimize the number of gates. The minimization of gates is what is really ...
0
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2answers
102 views
SN74LS26 2-input NAND gate. No output
I purchased SN74LS26N quadruple 2-input NAND Gates chips for my circuit. Before I insert any chip into circuit I test it on separate breadboard.
So I did with this chip and I get NO output when my ...
0
votes
1answer
99 views
What happens when you nand the same input?
I am trying to conceptually understand what happens to the output of the second nand gate when input into the 1st nand gate are combinations 00, 01, 10, 11.
0
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2answers
136 views
Circuit using only NAND gates
I am starting to get beyond frustrated with gates and breadboards now in general because of this simple circuit (which is literally experiment #1 in my digital logic class).
Using only NAND gates, ...
0
votes
1answer
33 views
Can I read programmed content inside any sort of non-volatile re-programmable memory device with Microscope, X-ray, etc.?
Non-volatile re-programmable memory like NAND flash, NOR flash, and etc. stores information in forms of electron charges and doesn't change in structural forms that can be inspected with X-ray or ...
0
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1answer
96 views
NAND flash pull ups
I am new to electronics, but always wanted to build my own devices and decided to start with simple usb flash drive as a first project. I found some reference designs by cypress and it confused me a ...
0
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1answer
101 views
Digital electronics design
Our professor asked us to name the pins of the gates as below based on a chip pinout diagram he provided which includes only NAND and NOR but in the circuit diagram, there's a negative OR gate.
Can ...
0
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1answer
59 views
Wear leveling and supply of voltage
Does anyone know if a NAND flash device (e.g. microSD) has to be continuously supplied with energy for its wear leveling algorithms work as designed? Or, if it doesn't matter if the device is (safely) ...
2
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0answers
555 views
File system to use with NAND Flash and 32 bit microcontroller
I am searching for a file system, suitable for NAND flash memory chips.
Currently I use a Micron 256MB SPI NAND flash memory where I write and read raw sensors data but without a file system and ...
0
votes
1answer
59 views
Can't read an entire page at once (NAND flash)
I am working for quite a while now with a GD5F1GQ4UCYIG from GigaDevice. The goal is to dump the content of the flash.
To do so I use a BusPirate. The NAND flash itself is still attached to the board,...
1
vote
1answer
590 views
TTL Logic Gate Resistor Values
I've been teaching myself the basics of circuits for the last few months and have been enjoying going into chip schematics. I'm trying to understand why the resistor values are as they are. For ...
0
votes
1answer
144 views
Converting gates in XOR circuit to NAND gates
I have this XOR circuit:
I tried to write it using only NAND gates and this was the furthest I got:
According to my book, it should look like this:
I did this:
$$(x.y')+(x' . y) = ( (x. y')+(x' . y)...
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0answers
150 views
Is there a need for a third transistor in a NAND gate?
I was attempting to create my "own" NAND-gate S/R latch using NPN transistors (I know there are ICs available for that)
From my own knowledge of how transistors work, I came up with this circuit for ...
0
votes
1answer
47 views
User controlled storage devices existence
Today's memory devices have a lot of logic embedded before data is actually written onto the NAND pages.
An example could be wear levelling algorithm , FTL functionalities etc.
The typical life of a ...
1
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1answer
146 views
Why is there no race around condition in NOR SR latch when S=R=0(initially)?
When the IC gets connected to the Vcc+, both the NOR gates get the input 0 and 0 (low) which yields the output 1. Now since both the outputs are again connected as one of the input to each of the NOR ...
0
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1answer
125 views
Output on Pass-transistor NAND gate lower than expected
I have an assignment to design an IC NAND gate, consisting og 2 NMOS-transistors and a designed inverter as seen in figure 1 and 2.
But when measuring the output at Vout, we only get about 60% of the ...
0
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1answer
249 views
1 TTL IC -> inverter + 2-input NAND + 3-input NAND
I came across this question in my homework:
Implement the following gates using only one TTL IC: one inverter, one 2-input NAND and one 3-input NAND.
The type of IC they're talking about has 14 pins,...
0
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2answers
230 views
Can anyone help me to understand what these capacitors do in this design?
I have a circuit design makes a button latch on-off and drive a mosfet. When I energize the circuit Vout that drives thr mosfet is initially low.
After pressing the button, the button state changes ...
0
votes
1answer
194 views
Using NAND gates to construct OR/AND gates
I have this Boolean equation
B'*C'*D' + A*C*D + C*D*E'
and I was just wondering how to use nand gates to express this equation.
With the schematic the inputs are
NAND1 it is B'*C'*D'
NAND ...
0
votes
2answers
472 views
use minimum number of NAND gates to realize this boolean expression [closed]
How should I proceed to find the minimum number of 2 input NAND gates to realize this boolean expression. I am allowed to use both complemented and non-complemented inputs.
$$F = X.Y + Y.Z + \...
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1answer
182 views
CD4011BE (DUAL INPUT NAND GATE) not working
I am using my CD4011BE NAND Gate IC. I connected a 9V battery in the 14th pin. And grounded the 7th pin. Then I provided input in the first 2 pins. I took a 330 ohm resistor from the third pin and ...
0
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2answers
400 views
Is there an intuitive reason for why NAND gate is a universal gate?
Now I know the maths and logic to figure out that every boolean function can be expressed using only AND and NOT gates, which in turn can be expressed using only NAND gate and hence every boolean ...
0
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1answer
847 views
Problem with NAND gate in proteus
I was doing a simple logic circuit in proteus when i realised that something was going wrong.
It looks like the NAND gate provides high voltage to its inputs from nowhere. No errors provided, but if ...
1
vote
1answer
399 views
momentary switch latching circuit
I'm very new at all this and hope you will have patients with me, I'm trying to use this circuit diagram to turn a momentary switch into a latching switch, I though it would be straightforward but ...
0
votes
1answer
434 views
Which input of NAND is preferred and why? [duplicate]
Let A and B be two inputs of the NAND gate. Say input A arrives at the NAND gate later than input B. To optimize delay of the two series NMOS inputs A and B which one would you place near to the ...
0
votes
2answers
93 views
Negative pluse generator does not reach 0V
I'm using an Arduino board to generate a 125KHz square wave signal to feed into this curcuit:
simulate this circuit – Schematic created using CircuitLab
So this is what I'm receiving from my ...
0
votes
1answer
176 views
Identifying this logic gate
Could somebody please explain the two logic gates with only the one input, A and B, respectively??
It is a NAND gate, with a box just before it.
What is this box?
Why only one input?
4
votes
2answers
3k views
More Fun with the CD4093 IC as Schmitt Trigger Oscillator. Any practical difference between circuit version with "Enable" pin and Without?
I built two Schmitt trigger oscillator circuits using the CD4093BE IC from Texas Instruments. The CD4093 is a quad NAND gate with Schmitt trigger inputs.
You can find the datasheet here: http://www....
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0answers
210 views
Which pins are required when reading and writing NAND flash?
I plan on reading and probably writing NAND flash on some embedded devices or USB flash drives.
I did not come across many examples for in circuit reading though I'd give that a try at first if ...
2
votes
1answer
63 views
Simplifying logic circuit [closed]
I've been trying to simplify a combinational circuit and wanted to know whether there was any simpler way of solving such questions. Do we have to find all the outputs and such or we can use a simpler ...
0
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0answers
56 views
Implementing with only NOR gates [duplicate]
I have an equation
y = ab + cb'
How would I implement this with only NOR Gates?
Thanks
1
vote
2answers
1k views
Minimum number of NAND gates to implement f(x,y,z,w)=x(y+zw)+yz'
As the title states, given a function \$f(x, y, z, w) = x.(y + z.w) + y.\bar{z}\$, what are the minimum number of NAND gates you need to implement f?
My first attempt at a solution was to draw a kmap ...
