# Tagged Questions

A decoder is an electronic signal processing circuit, which takes as an input a binary number, and turns on a corresponding pin accordingly. It takes n inputs (which can all be either on or off) and outputs 2^n outputs of which exactly one is on

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### Implement the following logic function using only one 4-to-16 line decoder and one 16x1 multiplexer : F1(A,B,C,D) = Σm(0,1,4,7,12,14,15)

I can implement the given function separately with a decoder or a multiplexer. What does the question mean when it says "and"? If I have to use both, how do I do that? I'm not very good with ...
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### Excess-3 to binary decoder using unused combinations of the code as don't-care condition

This problem is from my textbook chapter review question, and it seems a lot different from the example provided by textbook, so I have no idea what to do. I even have solution manual for this, but ...
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### VT pin flashing on RF circuit

The VT pin on the decoder side (signifying a valid transmission) flashes intermittently (sort of imitating a square wave pulse) This happens without me making any change in the circuit - no address ...
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### Implement a circuit with a decoder

I'm solving previous' years exams problems and i'm having trouble understanding one part of the problem. So I solve the first part and I have the truth table which is: I did elimination with ...
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### 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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### What is this component called

Suppose I have 512 leds in a 16 by 32 grid. I want to control what is displayed on the grid. To do this suppose I have a timer counter that is constantly counting between 0 and 31 in binary. This ...
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### Efficiently decoding a four bit input pattern into one of 16 twelve-bit output patterns

I have a four-bit input pattern. I have 16 distinct 12-bit output patterns. Many of these output patterns have a bits which are set in 2 or 4 of patterns. If I (arbitrarily) assign each pattern to ...
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### Is Turbo decoding modulation dependent?

I want to use the BER result of a turbo coded system from an article, but my system is not BPSK (and the article has discussed just the BPSK case). Now I wonder is Turbo decoder, modulation dependent?
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### What are the differences between line tree decoder and matrix decoder?

Here's the reference material which has me confused. After reviewing these 2 images I am confused about the differences between the 2 as the 6 to 64 decoder looks remarkably like a matrix decoder ...
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### What does grey dots represent in Proteus and why I am getting those

I am using a 5 by 32 decoder to implement a certain sequential circuit. However I am getting strange results. Here is the Snapshot: I don't understand why doesn't the decoder change its output when ...
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### Ideal multiplexers

I need thorough tests on different voltage biasing of an analog design. I figure all I just need to generate all combination of conditions (mostly voltage levels, some frequency) and port ...
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### BCD to 7 Segment is producing too little voltage

I am trying to use a BCD to 7 segment decoder to power my 7 segment display. This is the decoder I'm using (http://www.mouser.com/ProductDetail/Texas-Instruments/SN74LS47N/?qs=...
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### Building 3-8 decoder with two 2-4 decoders and a few additional gates

I am trying to build a 3-8 decoder without an enable by using two 2-4 decoders (that also don't have enables), two chips that each contain 4 AND gates, and one chip that contains 4 NOT gates. I have ...
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### Full adder using DEC 2/4

I want to design a full adder of one bit numbers using 2/4 Decoders and NOR gates. I have the truth table: Now, what's confusing me are the inputs and outputs. The inputs for one DEC would be A and ...
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### How to create a multiple active output decoder, not just one active output?

i have a project to controll lamp in cupboard. there are several button. okay, lets imagine there is 8 button. when i click 1st button its will turn on lamp 1, when i click button 2, lamp 2 is on. i ...
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### Looking for links to projects where video decoders are used as general purpose ADCs

The pricing for high speed ADCs is very high. However, since video decoders are used in just about every flat panel display, and these generally contain a couple of ADCs, their prices are very low. So,...
127 views

### How to implement line code?

I am looking for an easy way to implement a line code (both the encode and decode parts). This could be something like Biphase Mark Code, Differential Manchester, or anything else that has the ...
106 views

### Problem with glue logic/memory decoding on a 6502 project

I have a problem understanding the following schematic, specifically the "Glue Logic(Memory Decoding)" section in the lower half middle: This is a simple breadboard computer based on a 6502 CPU ...
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### How to terminate binary counting using a logic gate

So I am designing a 3-bit asynchronous binary counter which counts up to 11 then repeats using D flip-flops. That much I have done, however I am stuck when it comes to decoding the outputs to stop the ...
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### Realize switching function using only 2/4 decoders and logic gates

I am given the function $$f(A, B, C, D) = CD + A'B + BD'$$ The question states realize it using only 2-to-4 decoders and logic gates (if needed). My approach: Use 3 2-to-4 decoders, one with inputs ...
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### Designing logic for 7-segment display [closed]

I want to design the logic of a 7-segment display driver. As for the specs, I want it to have 4 inputs coding the binary value of numers 0-9 and 8 outputs for the display. I am not really sure where ...
2k views

### How to connect 16x2 lcd to esp8266?

I have ESP8266-01 this model I Updated the frimware to nodeMCU and uploaded the web server code and tested by blinking led via web browser. Now I want to test that if I can send text data from web ...
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### Inverting 3-to-8 decoder with all-active option

I have a requirement for an inverting 3-to-8 decoder circuit (i.e. all 8 output high except the selected one being low), but with an option to have all the outputs go low. The 74HC137 or 74HC138 is ...
248 views

### 7-segment display decoder

truth table for a 7-segment display decoder. It converts a binary input x[3..0] to a 7-bit code which drives each LED in an LED display am a bit confused can anyone just give a hint i want to produce ...
52 views

### Memory Question

Picture of memory bank and questions: for b) The CPU should use address 101100 to store A in chip 2 with the location 22. My thought process is that the first bit decides which ram chips will be ...
838 views

### How do I design 5-to-32 decoder using 2-to-4 decoder?

As there are 32 outputs in 5-to-32 decoder so I will have to use 32/4 = 8, 2-to-4 decoder. But then I have total 16 inputs. As I want to create 5-to-32 decoder so I need only 5 inputs, what do I do ...
122 views

### why there is no quad 1-to-4 demultiplexer?

I have 4 input signals to route on 4x4 outputs. it's not a 1-to-16 demux what i'm looking for. Outputs must be selected 4 by 4. is there any demultiplexer that can do that on one IC ? I didn't find ...
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### Memory design with 4 256K X 1 Bit IC's to a Z80

I have a couple of memory IC's lying around (16 of them) which I would like to use in my homebrew Z80 project. These IC's were produced by Samsung in 1988, the KM41256A 256K x 1 bit. I realise I can't ...
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### How come the decoder gives a question mark?

I'm using a scope to debug I2C (bit banging) by letting it capture the signal. I think that the output should be good, but the scope's decoder gives the following: where there is a question mark ...
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### Making function using 2x4 decoder and one or gate

I frankly don't understand how to make it. I try to make but, I think it's wrong. How can I make it ? Function is: $$f(a,b,c) = ∑(0,1,2,3,7)$$ My trying: In addition using 3x8 I make:
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### Using HT12E/D with RX/TX 433Mhz modules

i have ht12d and ht12e ic's and rx tx 433Mhz modules. i arranged the ht12e to the output port of Microcontroller and connected the ht12e to transmitter and similarly to the recieving side. is it now ...
29 views

### karnaugh to supplying to decoder

$$F(A,B,C,D)= Σ(1,7,8,9,13,15)$$ if possible, simplify then, make it by using decoders and logic gates. I've simplified it by Kmap and found as  F = \overline{B}\overline{C}D + A\overline{B}\...
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### Is there any difference between using a decoder for the alu op code vs using a multiplexer?

I am a programming student studying electrical engineering fundamentals on the side. I have come across two different methods for getting the result of an operation onto the bus. A decoder accepts ...
280 views

### Driving 50-pin e-ink display with one chip?

I'm trying to connect this 50-pin e-ink display to an Atmel ATmega328p for a hobby project. The biggest design challenge I'm facing is connecting all the pins from the display to the MCU in an ...
176 views

### Half Adder and Two Function, A Contest Questions?

I ran into a 2013 contest question on computer-science filed. What is the following True about F and G function. (The output ...
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### Logical Design Operation, A Simple Questions?

I'm so sorry if I ask my first question that so simple. My filed is Math and Computer science. I self-study Digital Design. My challenge is how we can find the operation of the two following ...
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### Calculate a function with logic gates

I have to build a circuit, with logic gates, that calculates a function $f(n) = 2^{2^n}$ where n is a 4 bit number. I can't figure a way how to do this. I tried to use 2-to-4 decoders but I failed. ...
389 views

### Design a Decoder using Logic Gates to display letters on a 7-Segment Display

The task I got is to design a similar circuit to a standard BCD to 7-Segment decoder, except only using Logic Gates and to display a eight letter character word, for example: SHELFLES As I have ...
286 views

### Implement a 2x1 MUX using 1x2 decoder

I need to implement a 2x1 MUX using a 1x2 decoder(We may also use 2 AND gates and 1 OR gate). I've made a start, but I'm kind of stuck. I thought, hey, I've taken a function table and implemented it ...
227 views

### How to construct a 10x8 ROM using two 9x8 ROMs

I used two 9x8 ROMs and used a decoder as enable for both ROMs. Now I have two 8 channel outputs from the two 9x8 ROMs, how am I supposed to make them into a single 8 channel bus? Or is my approach ...
705 views

### Encoder and decoder function [closed]

Can anyone explain the function of encoder and decoder with diagram.? Any help would be highly appreciated.
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### Using Enable to switch between two Decoders

I am trying to put an enable input in a 4-to-16 decoder so I can select between two decoder. Here is a schematic: I am using two decoders to select two different addresses in a 16x16 SRAM. I am ...
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### How can I make a 1K X 16 ROM chip with eight 256 X 8 ROM chips with an enable input and a decoder?

I came across this, which I'm guessing is correct, but I do not understand the shortcuts made here. What are the 8's with slashes through them? Do those represent 8 inputs and 8 outputs? And can ...
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### How input and output multiplexers work in ADV7800?

I was going through IC ADV7800 datasheet, getting confused with the functionality of two multiplexers given in its block diagram. Attaching picture of the same. For first MUX there is 12 inputs and ...
6k views

### How can I design a 4-to-16 decoder using two 3-to-8 decoders and 16 two-input AND gates?

I have an idea of how to get started, but not sure where to go from there. Since I am using two 3-8 decoders to develop a 4-to-16 decoder, I want to use 4 inputs out of the two 3-8 decoders. So I'll ...
503 views

### What's the difference between a decade counter and a “Divide by 10 counter”(MOD 10 Counter)?

I have a project of creating a digital clock out of multiple 7-segments. In order to display digits 0 to 59 in 2 7-segments which is better and easier to use: cascaded decade counters or a "divide by ...
122 views

### what will be the output of the nand gate in boolean form?the answer given in question is AB+BC+CA

the image shown below is a 3:8 decoder and s1,s2,s3 are the inputs to the decoder circuitry
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### Understanding decoders and comparators

How can I implement the comparator of two 2-bit numbers using decoders DEC 2/4 and required logic gates? That comparator will be used to compare two 4-bit numbers. The comparator only has one output ...