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0
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2answers
38 views

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 ...
3
votes
1answer
41 views

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. ...
2
votes
1answer
87 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 ...
0
votes
1answer
32 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 ...
1
vote
1answer
40 views

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 ...
3
votes
1answer
44 views

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 ...
-1
votes
3answers
124 views

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 ...
0
votes
1answer
1k 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 ...
1
vote
2answers
57 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
153 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
50 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
575 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
98 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
104 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 ...
3
votes
3answers
160 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
80 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
448 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
1answer
27 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
56 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
227 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
166 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 ...
3
votes
3answers
214 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
300 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
206 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
167 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 ...
-3
votes
1answer
371 views

Encoder and decoder function [closed]

Can anyone explain the function of encoder and decoder with diagram.? Any help would be highly appreciated.
1
vote
1answer
62 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
434 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
41 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
4k 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
354 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
110 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
2answers
425 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
3answers
670 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
104 views

Trouble understanding Verilog decoder logical left shift

This code is from asic-world: ...
0
votes
2answers
347 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
97 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
337 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
1k 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
1answer
178 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 ...
1
vote
2answers
2k 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
10k 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
3answers
1k 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
158 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 ...
2
votes
2answers
9k 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
155 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
150 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
109 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
81 views

Finding the minimum switching expression for this output

Did I do this correctly? ...