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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13 views

Compare numbers using flag registers

Suppose I have a four bit number. How Will I check whether the number is greater than or equal to zero logically by using flag registers? I can check if the number is equal to zero or not by Or ing ...
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1answer
21 views

Interfacing to a Microprocessor Bus without an 8255

There are 32 doors in a building each having a sensor attached with it. Each door outputs a signal 1 if it is open and O if closed. I want to design a pc based system to display the condition of each ...
1
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2answers
47 views

Designing a 8 bit ALU

I have started designing a 4 bit Arithmetic and logic unit. The sample image is as follows: The function Table: My question is: Is it possible to design an 8 bit ALU having the same ...
1
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1answer
53 views

Is it possible to see how much logic an IP core uses?

Is it possible to see how much logic an IP core uses in Vivado? I just found out that one of my variable might create a giant mux. I want to know how much logic this mux uses, so I could document it ...
0
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0answers
22 views

References on exercises in Analog circuits and Digital Circuits

Can you suggest me exercises' books (preferably with detailed solutions) on Analog circuits and Digital circuits as covered in Sedra and Smith's? I need as many exercises to practice to ace this ...
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0answers
32 views

Circuit tha does mult 2x2 bits and the result is in excess-3

I'm trying to implement a circuit tha does multiplication of 2x2 bits and the result is in excess-3 with only NAND'S. However, i did truth table and i simplified with Karnaugh's map, to make the ...
3
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1answer
47 views

Propagation delay of a digital logic circuit

I'm trying to answer a question on propagation delay. The question is: Assuming the propagation delays for different circuits are as follow: 4 ns for XOR gate, 3 ns for OR gate, 5 ns for NAND gate ...
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0answers
25 views

Calculation of a relation using only adding and shift [on hold]

I want to find the result of 5 · 33 − 3 · 64/2 using only adding and shift. How can I do this?
0
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1answer
26 views

how to design a multiplier digital circuit using 4bit adders with output in BCD?

I want to design a circuit that multiplies a number by 6 an input binary number using only 4bit full adders. I designed the combinational logic but couldn't do it with 4bit adders as i were asked in ...
0
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0answers
32 views

or gate with 74LVC02 pinout [on hold]

I screwed up, I somehow ended up with a quad or-gate in my designed labeled as 74LVC32 but the pinning I ended up with in my design was that of a 74LVC02. Possiblly I based the symbol for the or gate ...
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2answers
59 views

Digital Design for specified inputs [on hold]

I have one input which its states can be 1 or z (high impedance) and the result should be 1 and 0 respectively. Can anyone design a logical function for this? thanks. Edited Part: As you can see ...
0
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0answers
22 views

VLSI and Carry save adder (CSA) and multiple operand addition?

I read this PPT on page 146 we have this figure: as Better to have the same sum and carry delays (both contribute to critical path) in Carry save adder (CSA) and multiple operand addition. ...
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0answers
31 views

How do neuromorphic chips work?

I'm interested in physical hardware implementations of neural networks such as DARPA's SyNAPSE or memristor synapses. I've been looking around the web for a concise explanation to how these systems ...
0
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2answers
23 views

Half Adders and Full Adders connection

I found this strange thing upon my textbook as an exercise to "comment by its truth table". so I did the gargantuan truth table But there's nothing to "comment", as I see. The s2 = y0 reacts ...
0
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1answer
20 views

4-bit adder carry confusion

I try to design a circuit that adds two 4-bit binary numbers, but I get confused about the carry thingy. Above I add 0100 + 0101. The result should be 1001, but it shows 1100. buzzer Later I did ...
0
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1answer
46 views

Asynchronous JK Flip-Flop in VHDL

and thanks for your help. I wrote the code for an Asynchronous JK Flip Flop in VHDL, the code is the following: ...
0
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0answers
46 views

3 to 8 decoder made by 2 to 4 decoders

I found this thread of the exact topic I'm looking for at the moment and I tried to make it happen into multisim just so I could understand how it works. but at any combination of the switches, all ...
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0answers
22 views

F(a,b,c) = a’bc + abc’. \(a) NAND gates only, (b) NOR gates only [closed]

Draw a circuit using AND, OR, and NOT gates for the following function: F(w,x,y,z) = (w + x)(y + z) + wy + xz. Convert the circuit to a circuit using: (a) NAND gates only, (b) NOR gates only.
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1answer
55 views

Voltage on a disconnected part of the circuit?

Here's an RTL NAND Gate. I am trying to measure collector-emitter voltages of both transistors when both A and B are grounded. Transistor-A's collector voltage is about 3V. My multimeter reads C-E ...
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1answer
37 views

How to display 8-bit numbers on a 7-segment display [closed]

I designed a circuit for adding to four bit numbers and I want to display the results uisng two seven segment displays. How to do it ?
5
votes
1answer
108 views

Digital circuit to compare two voltages

I have a task in which I have two sensors, each reading a voltage value. I want a circuit to output 1 if the difference between the two readings is smaller than 10% and 0 otherwise. I can solve it ...
4
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2answers
845 views

Why two inverters in parallel?

My teacher of Electronic Instrumentation's course presented me on an exam the following problem: \$\hskip{75pt}\$ a) What is the importance of making the parallel between \$N7\$ and \$N8\$ ...
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3answers
71 views

Trouble finding the proper gate

I'm doing a full-adder using logic gates and I want to express the carry bit with a gate. So I found the minterms of the carry bit x'yz + xy'z + xyz' + xyz Is there a 3-input gate that does that ...
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0answers
61 views

How to protect IO pins from transient overvoltage?

I have a small PCB featuring a LTC2983 chip. I'm concerned about the possibility of transient overvoltage on the digital input pins (SCLK, SDI/MOSI, CS, Reset). The datasheet tells me that it detects ...
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2answers
49 views

What to do about two logic gates connected to the same wire?

If I have two logic gates (made of mosfets) with outputs connected to the same wire or bus, I encounter an issue where, when the logic gates are at opposite logic levels they are both trying to drive ...
0
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1answer
34 views

Logic Gates D Flip Flop

I'm using a program called Logisism and it has in-built features such as a D flip-flop: However it doesn't show how it's actually made out of logic gates. Can someone please show me a diagram of ...
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1answer
62 views

What bandwidth is needed for an arbitrary digital signal?

I am building a fiber-optic data link, with a laser driver and photodiode receiver. My goal is to transmit data at 50Mbit/s. I'm looking for what bandwidth this would take. Obviously 50MHz would not ...
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2answers
66 views

One Digital Logic Question in Previous Exam?

I Prepare for Entrance Exam on PhD, CS Filed. I ran into a previous question with following options (A to D from one to forth lines): The question is: if the input is always has valid values (no ...
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0answers
23 views

Quartus 2 double increase frequency

How can I create a up/down counter using quartus 2, that allows frequency to increase each time when you press and hold a button for 5s on the board
0
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1answer
36 views

Design 5 bit counter with two control inputs (direction and stop)

I am designing a 5-bit counter with two control inputs including direction (up/down) D and stop S. Here is how counter works: DS = 00: down (or decrease) DS = 01: don't care DS = 10: stop DS = ...
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2answers
109 views

Need help with sorting a 32 bit string

I have to program a combinational circuit which sorts a 32 bit array like this: 10011011010101101010101010110010 ==> 00000000000000011111111111111111 The input must be parallel and 32 bit. The output ...
0
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1answer
32 views

Multiplexer with enable at a karnaugh map

We have multiplexer 2->1 with reverse enable: (sorry for the child-like graphics) the function table is the following e c Y 1 X 0 0 0 x0 0 1 x1 I tried to make a karnaugh map, ...
0
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1answer
30 views

what should be the aspect ratio for 32nm and 45nm technology?

i am designing a combinational circuit and circuit worked well too. but i want to know if i directly write a net list rather than generating it through some schematic what should be the concept behind ...
0
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1answer
47 views

Upper and lower bound - Digital electronics

A logic signal is transmitted in a logic circuit with positive logic, where \$V_{IL}=2.3 V\$, \$V_{IH}=4.5 V\$, \$V_{OL}=1.4 V\$, and \$N_{MH}= 1.8 V\$ . Recall that when using positive logic, the ...
0
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2answers
105 views

What is the 14 pin IC that is associated with an ATMEL 312 24C02N IC? [closed]

Does anyone know what the 14 pin IC in this picture is? This circuit drives an RGB LED strip with 24 LEDs. The 14 pin IC does not have anything printed on the case. I understand that not having the ...
0
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1answer
58 views

Ladder Logic for PLC Program

Having trouble understanding this ladder logic program. I can solve more basic ladder logic programs but I do not know how to account for small voltage adjustments. Here is the problem: You are ...
-1
votes
1answer
56 views

Code on SMD component with only ADJF [closed]

I need to know what the part number is for a 6 pin SMD component. The code on the case is ADJF. Please let me know if anyone has a datasheet or information for this device. The circuit board is an ...
0
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0answers
36 views

Minimum delay path and sizing of CMOS gates

I've been wracking my brain for the past 3 hours trying to figure this one out, and all the examples I've seen just slap an answer on there like it's supposed to be obvious, which I can't for the ...
0
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1answer
68 views

Cons or pros related to connecting analogue and digital grounds together using a ferrite or inductor

I'm designing a signal acquisition system with an ADC. I have these questions: 1- Any cons or pros related to connecting the analogue and digital planes using ferrites or inductors. Or should I just ...
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0answers
23 views

4:1 multiplexer and 2:1 multiplexer

The question given as below: F1(A,B,C)=∑m(5,6,7) and F2(A,B,C)=∑m(0,6,7) Implement using 4:1 multiplexers and 2:1 multiplexers. 1.How can I implement them if I have 2 inputs? 2.How will be the ...
0
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0answers
60 views

On-off switch from PC's serial port

I am trying to make a circuit that can increase the number of loads I can turn on and off using a PC's serial port, since they are limited i thought of using a logic circuit based on th binary to do ...
0
votes
3answers
118 views

I want to learn how to make a CPU from scratch [closed]

I am new to electronics, I program from time to time and i know the basics of the logic gates. I have used logisim in the past and I was just wondering if someone could tell me about a good online ...
0
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0answers
14 views

showing truth tables for function composed of subfunctions

Hi I am having issues solving these types of questions. Below im asked to show the truth tables for $F$ and $G$. I previously asked a similar question create truth table of subfunctions based on main ...
0
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1answer
41 views

External Power Supply Grounding Scheme

The following are two possible grounding schemes for a sensitive instrument that contains high gain analog circuits and potentially noisey digital circuits: This circuit is connected to an external ...
0
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0answers
31 views

Determining and analyzing critical race condition from a transition table?

I have a question about critical race condition, and how to analyze one. I have read some posts on this forum, including: ...
3
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1answer
51 views

Fan-in with resistor?

Should the attached diagram have a fan-in of 4 or 8? Do resistors and resistance also count as a fan-in, since it acts like an input as well?
4
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1answer
81 views

Should I use an FPGA output for an MCU Clock?

We are laying out a board that was designed ages ago, the main purpose of the update is for part obsolescence. The board has several PIC uC's on it as well as an FPGA. Each of the PIC's needs a ...
0
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1answer
69 views

Finite State Machine Design for Entering/Exiting Door Sensor

I have attached an image of the assignment. I don't need to physically build it, just draw it using flip flops, mulitplexers, and logic gates. Not sure where to start at all. I appreciate any pointers ...
0
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1answer
28 views

Logisism Help - Building D Flip-Flop

I'm using the program Logisim to create very simple circuits as I am just beginning to learn about the different logic gates and such. In the Logisism program it has in-built features already such as ...
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3answers
64 views

Sequential circuit that divide by 5

How would one go about building a sequential circuit that produces an output of 1 if the input sequence of binary bits is divisible by 5? I've been racking my brain at this for a while but can't ...