Tips for intro to digital systems test?

In summary, the digital system teacher is hard and he gives question that ask you to design circuits such as make a counter that count 3 5 9 0 3 using mod-6 counter + encoder + decoder. Do question like this have a systematic way of solving or is only solvable if you have mad experience? He seems to give question that test your experience rather than steps. What should you do?
  • #1
david90
312
2
My intro to digital system teacher is hard. He gives question that ask u design circuit such as make a counter that count 3 5 9 0 3 using mod-6 counter + encoder + decoder. Do question like this have a systematic way of solving or is only solvable if u have mad experience? He seems to give question that test ur EXPERIENCE rather than steps. What should I do? I don't think I can do every problem because heisquestions have a big range.
 
Engineering news on Phys.org
  • #2
ok, some ideeas
a mod-6 counter is easy to made by resetting the counter when the output reaches 6 = 110b. So it will count 0, 1, 2, 3, 4, 5 for ever ... btw are you sure you didn't forget a number in your series?

the output of the counter goes into a decoder and the outputs of the decoder are scrambled to the inputs of the encoder according to the series you want to get.

PS: i would draw a picture but I'm a bit busy so I'll try later if you didn't understand...
 
  • #3
the example that I gave you was just a sample. here is the real problem.

Using a MOD-8 counter, 3 to 8 decoder and a 8 to 3 priority encoder, make a circuit that will count 0 > 5 > 2 > 7 > 4 > 1 > 6 > 3 > back to zero
 
  • #4
same things apply just use a 3 bit counter (that would be a usual mod-8 counter since it counts from 0 to 7)
 
  • #5
elaborate or give an example of what u mean by scamble
 
  • #6
OK, so your 8-bit counter counts from 0 to 7
When you put n (n beeing the output of the counter) on the selection inputs of the 3to8 decoder you get an level of 0 on decoder output n.
So in our example you will get the outputs of the decoder to have 0 logic in the order 0 to 7.
Then you connect output 0 of the decoder to input 0 on the priority encoder. Output 1 of the decoder will be connected to input 5 on the priority encoder. Output 2 of the decoder will be connected to input 2 of the priority encoder. And so on ... get the picture?
In this way when your counter is working at the output of the priority encoder you'll find your series. If you want another series just connect the decoder and priority encoder in a different way...
 
  • #7
"OK, so your 8-bit counter counts from 0 to 7
When you put n (n beeing the output of the counter) on the selection inputs of the 3to8 decoder you get an level of 0 on decoder output n.
So in our example you will get the outputs of the decoder to have 0 logic in the order 0 to 7.
Then you connect output 0 of the decoder to input 0 on the priority encoder. Output 1 of the decoder will be connected to input 5 on the priority encoder. Output 2 of the decoder will be connected to input 2 of the priority encoder. And so on ... get the picture?
In this way when your counter is working at the output of the priority encoder you'll find your series. If you want another series just connect the decoder and priority encoder in a different way..."


Thank you Guybrush Threepwood for saving my ass. I totally get what ur saying but there is a problem.

If you connect output 0 of decoder to input 0 of the PE, what will you do when the counter outputs a 4 and into the decoder and decoder output is 5? Not sure if I'm right or not but I think the output 0 of the decoder shouldn't be connected to anything to make the PE output a zero. countter > 0, input decoder >0, output of decoder is 0 and if u connect that to 0 input of the PE, wouldn't that make the PE output a 1 instead of zero?
 
Last edited:
  • #8
Originally posted by david90
If you connect output 0 of decoder to input 0 of the PE, what will you do when the counter outputs a 4 and into the decoder and decoder output is 5? Not sure if I'm right or not but I think the output 0 of the decoder shouldn't be connected to anything to make the PE output a zero. countter > 0, input decoder >0, output of decoder is 0 and if u connect that to 0 input of the PE, wouldn't that make the PE output a 1 instead of zero?

not sure I completely understand you but once the counter starts there is only one output active at one time for the decoder. So there's only one input for the priority encoder to interpret. Maybe you should tell how your decoder works (there are a lot of models of decoders out there...)

PS: may work computer is broken so expect some delay in my response ... :frown: :frown:
 

1. What is the purpose of an intro to digital systems test?

The purpose of an intro to digital systems test is to assess a student's understanding and knowledge of basic digital systems, such as logic gates, Boolean algebra, and digital circuits. It is often a foundational course for students studying computer science, electrical engineering, and other related fields.

2. What are some tips for studying for an intro to digital systems test?

Some tips for studying for an intro to digital systems test include reviewing class notes and materials, practicing with sample problems and quizzes, and understanding the underlying concepts rather than just memorizing formulas. It is also helpful to work in study groups or seek help from a tutor or professor if needed.

3. How important is hands-on experience in preparing for an intro to digital systems test?

Hands-on experience is crucial in preparing for an intro to digital systems test. It allows students to apply the concepts they have learned in class to real-world scenarios and solidify their understanding. Utilizing simulation software or building simple circuits can be helpful in gaining hands-on experience.

4. Are there any common mistakes students make on intro to digital systems tests?

Yes, some common mistakes students make on intro to digital systems tests include not fully understanding the material, rushing through problems and making careless errors, and not showing all steps in their solutions. It is important to thoroughly read and understand each question and to show all work to receive full credit.

5. What can I do to improve my performance on an intro to digital systems test?

To improve your performance on an intro to digital systems test, it is essential to attend class regularly, take thorough notes, actively participate in class discussions, and complete all assigned homework and practice problems. It is also helpful to seek help from the professor or teaching assistant if you are struggling with a particular concept.

Similar threads

Replies
17
Views
2K
Replies
1
Views
941
Replies
14
Views
1K
  • Electrical Engineering
Replies
6
Views
4K
  • Programming and Computer Science
Replies
17
Views
992
  • STEM Career Guidance
Replies
3
Views
2K
  • Sticky
  • Programming and Computer Science
Replies
13
Views
4K
  • Electrical Engineering
Replies
16
Views
3K
  • Electrical Engineering
4
Replies
138
Views
22K
Replies
9
Views
1K
Back
Top