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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11 views

How to design 4 bit binary counter with RCO?

I want to design a 4 bit binary counter with DFF,XOR,MUX,AND with synchronous load and enable with RCO output without using preset and CLR.
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1answer
47 views

How do FPGA's implement sequential circuits?

I know they implement combinational circuits using LUTs, but LUTs don't have feedback, so I don't see how they can be used for sequential circuits. So how do FPGA's implement sequential circuits? ...
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2answers
59 views

Data Whitening Block Diagram

I would like to understand this block diagram and how it relates to the formula: g(D) = D^7 + D^4 + 1 Supposedly this helps to generate a whitening word used within bluetooth radio, the empty boxes ...
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2answers
51 views

Design a 4-bit PISO shift register with 4 DFFs and 3 AND gates

I want to design a 4-bit PISO shift register with 4 DFFs and 3 AND gates. I have gone so far that these two designs can be implemented, but I can't go further minimizing it so as to use 3 AND gates ...
0
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1answer
30 views

How can I use an IO ports on Digilent Genesys Virtex 5 to drive 6 external leds?

I have a project which requires led output. Right now I'm using the onboard leds, but I would like to use 6 external LEDs instead. Which IO pins should I use, and how should this be done? I'm ...
0
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1answer
138 views

How do I analytically list the correct sequence for the given digital circuit?

Suppose given the digital circuit below, which contains 3 JK flip-flops: Assume that the sequence starts at ABC = 000. How can I analytically list the resulting sequence after every clock cycle?
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21 views

MCP23017 not causing interrupts using a normally open switch on power up

I'm working on a project where I am using two 4x4 button pads. I would need to use two MCP23017 for input interrupts to support the 32 buttons. I am using a Netduino and I'm coming across an issue ...
17
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10answers
4k views

Is there any way to use half-bits?

As most people here know, by using 4 bits, we are able to count from 0 to 15 (0123456789ABCDEF in hexadecimal). But if we were to only count up to 9, we would still be using 4 bits, and the digits ...
0
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0answers
29 views

How to implement a pipelined integer divider

I need to implement a pipelined integer divider for my 64-bit microprocessor. I have tried reading up on this, but I am still confused. Any advice would be appreciated.
3
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6answers
219 views

How to implement an 8-bit CPU?

I'm trying to create a CPU, using 8-bit instructions, and there will be 9 or 10 of them. I have an add, subtract, multiply, load, store, branch if zero, branch if not zero, print (to display), input ...
2
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2answers
106 views

Lots of thermistors but no readout

Back in Sep '12, Olin Lathrop answered a similar question about wiring a digital display to a thermistor, but my situation is slightly different from Jim McDerby's. I too have solar thermal panels ...
1
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2answers
54 views

How to Design D flip flop using T flip flop?

I don't know how to convert flip flops to each other but i know with any flip flop you can make all other flip flops.Please help me to how design it with specific way and explain step by step.Are ...
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0answers
42 views

VHDL code of johnson counter [closed]

For every 11th clock pulse the output goes high , so design it using a johnson counter . Also write the VHDL code ?
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1answer
26 views

How to calculate logic gates power in microwatts in Matlab?

I am designing a circuit in Matlab2014 Simulink using logic gates and I am giving Pulse and Constant at the input of the circuit but I cannot measure current and voltage at the output of the circuit. ...
1
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0answers
36 views

Digital to analoge voltage regulator

I am a complete beginner on electronics. I am trying to make device to control the voltage output according to a digital input. So basically what I need to make is to continuously increase the ...
3
votes
2answers
251 views

Why is shift register very important?

I learned about shift registers a few weeks ago but I don't know why it is very important and everyone said that it is necessary for microcontroller, etc. Please make sense for me.
2
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1answer
65 views

Is there relation between logic chip names and their internal structure

I know that for instance an ATMega328 is a 8 bit MCU with 32k of program space, the same can be said for most other MCUs and some other ICs with a direct relation between the name and internal specs. ...
0
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0answers
48 views

Arduino Output to 24V logic

We are testing out some analog sensors, and we need to send a 24V trigger (maximum 15mA) to a PLC from an arduino. I have seen some designs using a MOSFET to make a bidirectional logic converter, but ...
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1answer
63 views

Transistor count in NAND or NOR implementation of boolean algebra?

I have a complex output function in boolean algebra ( Where '~' means NOT): F=~( (a c ~d) + (a ~c ~d) + (~a c) + (~ a c d) + (a c ! d b) ) I know this can be simplified down to: F = (~a ~c) + (a d) ...
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1answer
51 views

What are “consecutive input pulses”?

I am stuck on a homework problem that I have difficult time understanding: Draw the state diagram of the circuit described below, with detailed explanations: A detection circuit has two ...
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2answers
140 views

Constructing decoder 5/32 using smaller ones, without enable

I need to construct a decoder 5/32 using any number of 2/4 and 3/8. How do I start? With Enable it's not hard to figure out, but without them it gets complicated. Advice?
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0answers
57 views

Which logic gate arrangement would be better?

I have converted an old ATX PSU to a portable power supply for traveling as it is reasonably small. To go with it I will also make up a visual indication as to the state of the PSU once on, this is to ...
5
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3answers
379 views

IC takes no input (or high) as high and low input as low on breadboard

I was working with IC 7400 (or LM74LS00 / NAND) (and IC 7486 - XOR) to design and verify combination circuits and logic gates. Consider the lower end of breadboard as LOW (connected to GROUND) and ...
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1answer
72 views

Finding Critical Path of Combinational Logic

I have a combinational circuit and I would like to find its critical path in design compiler. Essentially, I want to find out by how much the combinational logic will reduce the maximum clock ...
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0answers
39 views

How can I connect this ram-ish memory layout

In the picture on the web, I want to connect the two inverters that are ringing around each other, I want to connect them to the data-line. I can't seem to figure out how to properly connect them in ...
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51 views

Designing a 4 bot non binary Synchronous up down counter using a 4 bit binary counter (MOD 14)

The following Image is the "design" of the counter I need to make, I should only need a few extra simple gates in order to achieve a 4 bit Synchronous down counter that is NOT binary. So far I've ...
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2answers
73 views

How can I add sounds to my logic probe?

I am a beginner at electronics and I want to build a simple logic probe for TTL circuits. I found this diagram online: Which does exactly what I want. However, I would like to make it play a high ...
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1answer
51 views

What does a double array do?

While looking through some Verilog code, I came across this: input [7:0] data [0:16] The code referred to this as memory. Could someone explain what it does? I ...
0
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1answer
40 views

Howto convert “0=floating / 1=Vcc” to CMOS compatible “0=ground / 1=Vcc” signal

I'm playing around with CMOS logic using CD#### dip packages. As far I understand input pins should never be left floating, always connect them to Vcc or ground. Unfortunately my digital source ...
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0answers
44 views

Why TTL logic gates are faster when compared to CMOS logic gates? [duplicate]

In TTL families resistors are used and number of stages between input and output terminals is comparatively high. Still operation speed of TTL is better than CMOS. Why?
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2answers
107 views

What's the difference between a SRAM cell and a D-Latch?

They both seem identical - they both have an "enable" and a single input. When enable is high, the value stored in the element is set to the input. Are they functionally different in any way? (I know ...
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1answer
56 views

How can I read in an image in Verilog?

I have a .mif image that I want to encrypt in Verilog. To do so, I need to read the image into the program and store it in an array. The image would be 160 by 120 and I would like to store it in an ...
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1answer
42 views

FSM for predesignated process (How to draw the state diagram)

let me start by saying this involves some homework problems so if you could help guide me a bit I would greatly appreciate it. I have been working with finite state machines for a bit in my course ...
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78 views

Design a Mealy FSM that functions as a sequence detector, generating two outputs y, z in the following way:

Initially both inputs are set to 0. Output y is set to 1 when the sequence "10" has been applied to the input x; output y should then be reset to 0 and y should continue detecting next occurrence of ...
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2answers
66 views

How does Decimal Mode in an ALU work?

Trying to wrap my head around the basic of how to do decimal addition in an ALU. Here is what I have so far. I am primarily looking at the MOS 6502 CPU architecture. It has two modes in which you ...
0
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0answers
40 views

Parallel-in, parallel-out, universal shift register

I am trying build circuit of parallel-in/parallel-out universal shift register. I have found circuit in the Internet. Here it is I have tried to do this using MicroCap , but it doesn't work as ...
0
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1answer
31 views

Modelling priority/importance in a digital circuit

I'm attempting to create a digital circuit that has three inputs representing binary numbers. For example 001 would equal 1 in decimal , 011 would equal 3 and 111 would equal 7. So overall the highest ...
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2answers
323 views

How do you do operations on large numbers using a small fixed-width ALU?

I am wanting to design a simple calculator like what you would find in the dollar store. Something like this: This little guy can display a number 8 digits long, meaning 99999999 is the largest ...
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0answers
49 views

4:2 compressors gate count increasing but area decreasing, How?

From literature's I got below definition, ...
0
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1answer
49 views

Truth Table for JK flip-flop circuit?

Given a JK flip-flop circuit (using a D flip flop with a 2 by 1 MUX) how can I derive a truth table from this circuit? D = JQ' + K'Q Note: This is NOT a homework question. I just simply want to ...
1
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1answer
106 views

Need help with a R-2R DAC Circuit

I am trying to simulate a 4-bit DAC circuit using a R-2R resistor ladder. I am using a 741 op-amp. I selected the R value as 10k and calculated the value of Rf using the equation given on this page - ...
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3answers
341 views

NAND gate that outputs 0 when all inputs are 0

I'm trying to work out a piece of binary logic and this is essentially what I am trying to achieve: ...
0
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1answer
85 views

Parallel MAC unit based on modified booth algorithm

The below diagram is the parallel MAC structure. In parallel MAC both partial product addition and accumulation take place at same time. The partial product summation + accumulation unit of above ...
0
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0answers
45 views

Using explicit registers in RTL designs

Is it a good practice to use explicit register IPs in RTL designs? For instance, having separate IPs for each type of register and instantiating them in the design instead of coding them on-the-fly. ...
4
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2answers
162 views

How does someone initially design a digital system for HDL?

So I have really been hitting the example code hard this week in an attempt to better understand some HDL design basics, specifically FPGAs with VHDL. The book I am using (if anyone is interested) is ...
0
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0answers
29 views

Help with harder version of carry chain adder?

I am designing an addr circuit given cin = 0, given a nand of the operands i want to add, their xor, and nor. I have drawn it in a software but i am not getting the right output, i have tried to ...
0
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3answers
80 views

Does it take long to implement RSA in hardware?

I just finished my first Digital Hardware course. We covered combinational circuits, sequential circuits and FSMs. We now need to create a final design project. We have 2 weeks to do so and we work ...
0
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1answer
222 views

Remainder of a 16-bit number divided by 3

I have to design a combinational logic circuit which accepts a 16-bit number as input and then calculates the remainder of the number divided by 3 as its output. I originally had no idea how to ...
0
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2answers
75 views

Is possible to use wave guide to decrease beam width?

If I use a normal 1/4 monopole antenna "30 MHz for example" and cover it with metallic wave guide has a narrow beam width, should the gain increasing according to this formula below? $$G = 10 \; log ...
0
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50 views

AND gate mysteriously and ludicrously slow

I've made a 3 input AND gate from 4 NANDs in order to daisy-chain 3 motor drivers jrk 21v3 and get the current value out of them. The problem is, the command is sent OK, the driver responds OK with ...