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2answers
43 views

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 ...
0
votes
3answers
79 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 ...
0
votes
1answer
45 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 ...
-1
votes
1answer
167 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
votes
1answer
79 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 ...
0
votes
2answers
50 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 ...
0
votes
0answers
27 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: ...
3
votes
2answers
106 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 ...
0
votes
1answer
55 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:
-2
votes
1answer
232 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 ...
0
votes
0answers
92 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
votes
1answer
21 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 + ...
1
vote
3answers
32 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 ...
0
votes
3answers
155 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
votes
1answer
146 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
votes
0answers
55 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
votes
3answers
122 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 ...
-1
votes
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
vote
1answer
120 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 ...
-1
votes
2answers
99 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 ...
1
vote
1answer
69 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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votes
1answer
81 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
vote
1answer
52 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 ...
1
vote
1answer
126 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
votes
1answer
32 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 ...
0
votes
2answers
774 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 ...
0
votes
1answer
124 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 ...
-1
votes
2answers
96 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
0
votes
0answers
98 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 ...
0
votes
2answers
161 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 ...
0
votes
0answers
115 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 ...
0
votes
3answers
111 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 ...
0
votes
1answer
51 views

Trouble understanding Verilog decoder logical left shift

This code is from asic-world: ...
0
votes
2answers
207 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 ...
0
votes
1answer
72 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 ...
-1
votes
1answer
180 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.
1
vote
2answers
821 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?
0
votes
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
votes
1answer
121 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 ...
0
votes
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 ...
1
vote
2answers
924 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
votes
1answer
6k 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 ...
0
votes
0answers
884 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 ...
0
votes
3answers
742 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) ...
0
votes
3answers
127 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 ...
1
vote
2answers
5k 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 ...
0
votes
2answers
127 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 ...
2
votes
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
votes
1answer
93 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
votes
1answer
70 views

Finding the minimum switching expression for this output

Did I do this correctly? ...