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43 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 ...
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1answer
55 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 ...
0
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1answer
62 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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2answers
40 views

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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0answers
10 views

84(-2)(-1) code to 2421 code using decoders

I have a question on how to make a circuit using two 3x8 decoders with enables and 4 logic gates to create 2421 code from 84(-2)(-1) code. the input\output table is as follows: ...
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2answers
99 views

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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1answer
48 views

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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1answer
93 views

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 ...
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0answers
52 views

Making 2x4 decoder by using 1x4 demux

As far as I know, 2x4 decoder has 2 control signals and 4 outputs. 1x4 demux has 1 input, 2 control signals and 4 outputs. And again As far as I see, Just difference is 1x4 demux has a 1 input. So, If ...
0
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1answer
20 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 + ...
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3answers
31 views

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 ...
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2answers
104 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 ...
3
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1answer
102 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 ...
0
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0answers
47 views

What is Line-Locked Clock?

I was going through data sheet of one video decoder IC. Where I came cross this term Line-Locked Clock (LLC). There is one LLC out pin. What I think is, it this same as pixel clock. When ever one ...
3
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3answers
106 views

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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1answer
61 views

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. ...
1
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1answer
79 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 ...
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2answers
82 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 ...
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1answer
53 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 ...
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1answer
63 views

Encoder and decoder function [closed]

Can anyone explain the function of encoder and decoder with diagram.? Any help would be highly appreciated. Thanks.
1
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1answer
48 views

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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1answer
101 views

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 ...
0
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1answer
27 views

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 ...
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2answers
454 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 ...
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1answer
105 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 ...
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2answers
83 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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0answers
93 views

Given a Boolean Function, Represent it with a 4-16 inverted decoder

The Question Given a function F(w,x,y,z) = ProductOfMaxTerms[0,4,5,6,7,9,10,11,12] implement F using one inverted 4-to-16 decoder (positive enable) and a NAND gate My Work Since it's an inverted ...
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2answers
138 views

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 ...
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0answers
114 views

Inverted 3 to 8 Decoder

1.write a boolean equation for an inverted 3 to 8 decoder. 2.draw the circuit as a module So far, I have this equation, and hoping this is the answer for the Q1. mo = s2's1's0'EN = 0, others = 1 ...
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3answers
98 views

Implementing a boolean function using a decoder

I am taking a course in computer organization, and currently struggling with circuits. I was stumped by the question below. I drew the K-map for the boolean function and managed to obtain a ...
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1answer
47 views

Trouble understanding Verilog decoder logical left shift

This code is from asic-world: ...
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2answers
161 views

Best way to use multiple decoders for an LED matrix

I'm designing a 16 x 32 RGB LED Matrix and its controller / driver board. So I've designed a couple of solution approaches and I'm wondering if there is a better way to drive multiple 4 to 16 line ...
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1answer
67 views

How to generate bar using decoder

Ic74154 decoder generate active low o/p i.e for example if input is binary 5 , 4 becomes low. I want a circuit which will give output when i/p is binary 5 then o/p is low for 0 to 4.It is possible by ...
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1answer
166 views

Is it possible to create a 4-16 decoder using five 2-4 decoders without enable inputs?

So that the outputs represent a 4-input truth table.
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2answers
746 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
75 views

what is superposition coding?

In the context of multiple access techniques, there is a coding scheme called "Superposition Coding" or particularly "Superposition Coding with Successive Decoding(SCSD)". I surfed the internet, and ...
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0answers
15 views

Design a 4-to-12 decoder using only 2-to-4 decoders [duplicate]

I'm not particularly comfortable with decoders, and was curious as to what the easiest way to create a 4-to-12 decoder using only 2-to-4 decoders.
0
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1answer
110 views

Decoders and Logic Gates [duplicate]

I have two questions. First, I've been staring at this problem for over an hour and I'm stumped. To be clear, I'm not looking for the answer, just some hints to get going would be helpful: 1) Using ...
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0answers
28 views

Implementing a decoder along with nothing else but a single NOR gate [duplicate]

To start it off I will be plainly honest here, this is homework, but I know that it's not a good idea to ask for help without trying it first obviously. So, I have done the work, but I am still ...
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2answers
801 views

How do I implement F using one 4-16 Decoder and a NOR gate?

I currently have more than 50% of question done I believe, but what I don't get is that why does the question ask me to use a NOR gate. Doesn't that change the value of F. For example, if I have 0000 ...
2
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1answer
5k views

Design a 3-to-8 Decoder Using Only Three 2-to-4 Decoders

Using only three 2-to-4 decoders with enable and no other additional gates, implement a 3-to-8 decoder with enable. The inputs of the resulting 3-to-8 decoder should be labeled X[2..0] for the code ...
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0answers
790 views

Implementing a boolean function using decoder and or gates

I am trying to implement the negation of a set of minterms. As a result my function looks something like: \$(A+\bar{B}+C)(\bar{A}+\bar{B}+C)(\bar{A}+\bar{B}+\bar{C})\$ I know how to implement it if ...
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3answers
683 views

How to make 7-segment display count up ?

I've connect 7447 decoder and 74193 counter as shown in the picture but I have not used 555 timer yet. Is there any way to test the circuit before using 555 ? I've connected the pins (up and down) ...
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3answers
117 views

Switch between two digital signals with no microcontroller

I'd like to use an Arduino to send wirelessy (RF 433MHz, probably) two different digital signals to pilot two different relays (later they will be much more). I know probably this is something very ...
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2answers
4k views

How to connect 7447 decoder to 7-segment display?

I've connected a 7447 decoder to 7-segment display as shown in figure. When I connect an input, the LEDs doesn't form numbers but they light up randomly. I just want to know the right way to ...
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2answers
123 views

Signal-driven 3 output logic gate decoder or switch?

I need to build a simple logic gate circuit such that when a single input signal or switch goes low it alternately activates one of three outputs as high. That is, every time it goes low the currently ...
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3answers
129 views

State Machine w/ Decoder

I'm trying to design a State Machine that acts as a synchronous lock. There is only 1 input (X) and one output (Lock= 0, Unlock = 5v). The machine will only unlock if the following order is put in: 0* ...
0
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1answer
85 views

G.711 for dummies

I am in midst of some online telephony course, and there are questions regarding which I have no one to ask but this community. G.711 volume encoding. I have some difficulty to understand how ...
0
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1answer
67 views

Finding the minimum switching expression for this output

Did I do this correctly? ...
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3answers
1k views

74154 4 to 16 decoder logic diagram

Will someone please explain the purpose of inverting the outputs (0 through 15) as well as the use the NAND gates here? 2nd, less important question: why are there two input G1 and G2 if the ...