Digital electronics use a finite number of states, unlike analog electronics that treat continuous signals. Digital logic is used to perform arithmetic operations with electric signals, and constitutes the base for building CPUs.
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1answer
45 views
NAND and NOR logic gates
What would be the diagram of following logic gate function by using NAND and NOR IC’s?
F = AB + BC + AC.
Kindly help how to draw its logic diagram?
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1answer
54 views
Why memory is divided into row column grid? [on hold]
Why memory is divided into row column grid? And why large memory slows down access time?
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2answers
46 views
How to connect an AND gate with a shift register
I'm new to using flip-flops, and making them into shift registers, but what I'm trying to do is turn on a logical AND gate based off the input of two flip-flops. The scenario is: first, a room light ...
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1answer
144 views
Transistor count
I'm completely stumped on where to start with this, any point in the right direction would help. The work gave me a circuit drawn out and asks 2 questions:
1)Determine the number of transistors ...
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1answer
44 views
Converting Positive Logic to Negative logic. 7 Segment Decoder
I was looking for a truth table for a seven segment decoder and saw that in order to display a three we must input a 0 for D, 0 for C, 1 for B and 1 for A. This will allow us to output the segments ...
0
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0answers
49 views
How does a software intruction materialise to hardware action? [duplicate]
Please feel free to rephrase / reinterpret the question.
Rephrased - RM:
How does a program which can be represented by high level language commands or opcodes or a series of 1's and 0's get ...
2
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2answers
75 views
Can anyone tell me any exclusive application of Johnson counter?
I went through many types of counter in my digital electronics text book. Each one was interesting. When I came across Johnson counter, I was not able to figure out any practical application. Can ...
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1answer
42 views
Output table equivalent to state diagram?
I have the following state diagram to which I am supposed to construct an output table for. I have the answer, but I do not understand how they derived this output table?
If someone could explain one ...
-4
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0answers
32 views
Logic Gates.AND .OR gates [duplicate]
Kindly help about this question?
If more than two inputs AND & OR gates are available, how will we connect its inputs so that they work as 2 input gates? Perform it for 3 and 4 input AND & OR ...
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2answers
75 views
Memory mapping in the 8085 microprocessor
In the 8085 microprocessor there is 64 kb of memory available of which some are assigned to ROM while others are assigned to RAM. My question is, why is ROM always mapped to a lower region of memory ...
-7
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0answers
50 views
DIGITAL ELECTRONICS (COMPUTER SCIENCE) [closed]
what is the limitation of DTL gates
Explain the application of up and down followers
16-bit up binary counter using JK flip-flop
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1answer
44 views
detector circuit sequence [duplicate]
How can I solve this exercise?
Design a circuit with 2 input X,Y and 1 output Z, that be able to identify the following sequence of inputs:
00,10,00,10.
The output Z must assume the logical value 1 ...
0
votes
2answers
51 views
External Clock Input to Microchip Microcontroller NOT Gate?
I'm using a PIC24FJ256GB110 connected via SPI to a CAN Bus Controller chip MCP2515. The MCP2515 requires a crystal connected to it but has a Clock Output pin for driving a connected MCU. So I was ...
-1
votes
3answers
80 views
Digital Logic design(Logic Gates)
If more than two inputs AND & OR gates are available, how will we connect its inputs so that they work as 2 input gates? Perform it for 3 and 4 input AND & OR gates.
How it will be done?
6
votes
3answers
430 views
3-bit multipliers - how do they work?
I need to understand how 3-bit multipliers work and then I must design one. I've read through Wikipedia's binary multiplier but I just can't wrap my head around it. I don't understand where to start. ...
0
votes
4answers
148 views
AND, OR gates: 3 transistors. NAND, NOR gates: 2 transistors. Why? [closed]
Why do NAND and NOR gates require two transistors each, whereas AND and OR gates require three each?
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1answer
46 views
Design for test - What the different ways in which this is done
I know that when we are designing digital circuits we may add porition to it that helps in testing it. This may go beyond merely boundary scan test. What resource can I can use to understand this ...
0
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2answers
50 views
design data storage using a simple MUX instead of a complicated SR latch
I was studying sequential circuits and I am at the very infant stages of the course. After studying the D flipflop I realized that the purpose was to let the data line change the output if clk=1 or ...
2
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0answers
66 views
4 cell bath scale to Arduino what is circuit? [closed]
A bath scale has 4 cantilever beam load cells; one at each corner. Each beam is fitted with 2 strain gauges glued to one side of the beam and three lead wires, Red, White, black, go out of the cell to ...
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3answers
105 views
D flip-flops, but no feedback loops: impossible?
Using JK or T flip-flops, it's easy to create a synchronous N-bit counter by cascading them as depicted here:
The above circuit has no feedback loops in it. I have run into a situation where I ...
0
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0answers
28 views
Meaning of GS output parameter in TTL octal encoder (LS148)
LS148 encodes eight data lines to three-line (4-2-1) binary (octal). We had an experiment wherein there are eight push buttons corresponding to decimal inputs from 0 to 7. In our experiment, the state ...
-4
votes
3answers
55 views
Proof of logic gates
I have to prove:A’B’C’P+A’B’CP+ A’BC’P+ A’BCP’+ A’BCP+ AB’C’P+
AB’CP’+ AB’CP+ ABC’P+ ABCP’+ ABCP = P + BC+AC
I have done this: P(A’B’C’+ABC+ A’B’C+ ABC’+ A’BC’+ AB’C+ A’BC+
...
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votes
2answers
40 views
How to get equivalent behaviour of NOR and Nand gates, by making changes on the input side, when their inputs are attached
I have two input NAND and NOR gates, I have attached their inputs and they both give the same result as the NOT gate, that is the inverter. Now i want to make further changes at the input side, so ...
0
votes
1answer
80 views
What's the first step to learn Verilog coding to sort values?
I do not know how to start working on this problem. Should I first design the digital circuit of sorting? I am poor on both topic. Suppose I have four numbers R0, R1, R2, R3... What is the digital ...
0
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2answers
47 views
Digital-to-analog conversion of a product of digital inputs
If we have a 4-bit DAC, which converts a 4-bit binary signal \$ X = X_3 X_2 X_1 X_0\$ to an analog signal \$Y=X/2\$ (i.e. 1010 -> = 5 V, or 0111 -> 3.5 V).
How can we create a DAC, using any number ...
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1answer
99 views
Maximum safe clock frequency of full adder circuit
A full adder consists of 2 xor gates, 2 and and 1 or gate. The propagational delay of any of these logic gates is 8 ms. I have to find out the maximum safe clock frequency. As there are total 5 ...
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1answer
51 views
How to convert a boolean expression to a NOR gate only format using Demorgan's law
My boolean expression is D+ CD' (A+B) . Only 2 input NOR gates are available.
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2answers
54 views
Limitations of using minimum no. of MUXes for a given boolean function
Given a specific Boolean function, is there any restriction on the minimum no. of multiplexers required to implement that function? Is there any theory on that?
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3answers
130 views
Physical understanding of a clock cycle
I am a software developer (using high level languages like .NET,C,C++ etc) trying to understand how computers work at a lower level. I never studied any Electrical Engineering at university. I did ...
0
votes
1answer
47 views
Connecting multipliers to increase operation bit width
I successfully created a 2 bit digital multiplier. Can I use that 2 bit multiplier to create a 4 bit multiplier and then use that to create an 8 bit multiplier and so on? What I basically mean to ask ...
0
votes
2answers
89 views
Can I get the NOT of 3 inputs using as many and/or gates but only 2 NOT gates?
Came across this question in an online course. I think it belongs to electronics and logic alike.
EDIT: To clarify, if I have A, B, C as inputs, I need ~A, ~B, ~C as outputs, separately.
EDIT-2: So ...
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1answer
39 views
Adder hardware logic
simulate this circuit – Schematic created using CircuitLab
If this circuit is a part of a 4 bit full adder, where A1,B1 are adder inputs and C1 is carry in from previous bit, does C2 give ...
4
votes
3answers
156 views
Capacitor that stores one bit of information
I am a software developer (using high level languages like .NET,C,C++ etc) trying to understand how computers work at a lower level. I never studied any Electrical Engineering at university. I did ...
0
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2answers
74 views
Flip-Flop Trigger with switch on Input and two Outputs (low and open but not high and low)
Can some one recommend a simple circuit for flip-flop trigger.
On the input side it must have one switch between Ground and Input.
On the output side it must have two flip-flop outs but when first ...
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1answer
45 views
Using RF Link Transmitter/Receiver - ADC vs Microcontroller?
I have a sensor that gives off 4 volts when actuated and I would like to transmit it a distance to a light. So I found these RF Link Transmitter/Receiver at 434MHz:
...
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3answers
109 views
Subtraction using adder circuit
I need some really basic help here. Can I use a 4bit adder chip as a subtracter by using the 2's complement for the number to be subtracted?
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2answers
59 views
Is D flip flop can be combination circuit?
I read that circuits are two type combinational and sequential. In combinational circuit the output depends on present state/input i.e the previous state do not effect the present output. but D flip ...
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3answers
54 views
Logic phase shift detection
I have two logic signals that can be in two different configurations as shown in the image below.
I would like to output a third signal that is HIGH for case A and LOW for case B. How can I ...
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3answers
71 views
What is meant by logic high or low
In a circuit involving integrated circuits, the documentation for the ic often states that if a pin is in logic 1 or high the circuit will behave in one way, and if the circuit is in logic 0 or low ...
18
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2answers
1k views
Why does connecting a high-current device to my digital circuit cause weird behavior?
I have a
arduino
microcontroller
other digital thing
and when I connect a
motor
pump
heater
other high current thing
I experience
weird ADC measurements
reboots
crashes
errors in digital ...
-1
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1answer
113 views
Logic gates q's on unconnected and mid-range inputs and gate output
Why do TTL integrated circuits assume unconnected inputs to be at logic 1?
What is fan-in and why is it important in the operation of a logic gate?
What happens to the gate output of NOT logic gate ...
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1answer
96 views
how to draw a timing diagram for a logic circuit
Hello does anybody have a guide to drawing timelines for logic circuits? For flip flops like this
Basically I want to draw corresponding timeline for any circuit like this:
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1answer
44 views
working of an sr latch
I am confused with the working of an sr latch.
simulate this circuit – Schematic created using CircuitLab
The two inputs provided to nand1 is S and q2 and the inputs provided to nand2 is ...
0
votes
2answers
42 views
query related to latches
I had two doubts about the working of an s-r latch. One is, when we apply a clock signal along with the s and r inputs to the gates, how do we administer the time after which the clock signal changes ...
2
votes
1answer
98 views
Is there a difference between TI brand of the 74HC595 and the NXP brand?
I have been trying to figure out the functional differences between TI's version of 74HC595 and NXP's version. I've been looking at the function tables in the datasheet for TI and the datasheet for ...
2
votes
2answers
117 views
Logic gates and logic circuits
I understand logic gates and their truth tables. However, when it comes to the circuits of the gates, I have trouble understanding them. Could someone please explain how a gate such as the following ...
0
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1answer
40 views
Function setting on SPLC780D LCD
I'm drawing a bit of a blank with this. I have a 1602A-1 16x2 LCD screen hooked up to an i2c port expander chip.
I'm using the screen in 4 bit mode so I have DB4-7 hooked up to GPIO 0-3 respectively.
...
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1answer
56 views
What is the simplest way to toggle a relay with analog feedback?
I've been playing with electronics for a long time, but am fairly new to digital electronics, including using Fritzing, so apologizes in advance for that.
I'm attempting a fairly basic ...
0
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1answer
74 views
Is this circuit a viable implementation? [duplicate]
Following on from an earlier question where the implementation was flawed, can anyone advise if the below is a viable implementation of a circuit to handle a matrix keypad?
The idea is that one ...
1
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1answer
78 views
2 logical inputs on the same circuit
Is the below a valid circuit implementation and are there any things to watch out for? It's a simplification of the larger circuit but the crux of it is that I need to sink current into two GPIO input ...
