# homework problems:

#### infinitig35

Joined Mar 3, 2008
25
Good morning all. I have several homework problems that I would like some input on. I have attached the questions below. Thanks for all your help.

#### infinitig35

Joined Mar 3, 2008
25
hmmm, somehow my attachments did not work. I gues the file size is a liitle too big. Let me try again.

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#### recca02

Joined Apr 2, 2007
1,214
For some of the question google is your friend, for the rest it would be better if you posted your attempt at it first.

#### S_lannan

Joined Jun 20, 2007
246
yeah, you have to tell the guys what is confusing you. there are plenty of sites that will offer to solve homework sheets for money. but if you wanna learn....

#### infinitig35

Joined Mar 3, 2008
25
The title of this section is "homework help" right? Why u guys giving a hard time? There are 20 questions and I answer them all except for these couple that I posted here.

#### Dave

Joined Nov 17, 2003
6,970
Can I ask all members to keep answers constructive. Anyone is free to ask questions for help.

As for you questions:

17 - see http://www.geocities.com/sujoymukherjee_82/file1/digitalclk.pdf

18 - see http://www.allaboutcircuits.com/vol_4/chpt_11/3.html it should give you sufficient to deduce the answers. You may need to do a little think for b)-d).

14/15 - see http://www.allaboutcircuits.com/vol_4/chpt_8/6.html for worked examples of this type of question. Have a go and post up your answers - it is a long time since I did any Karnaugh mapping but I'll be happy to check for you.

16 - Where f = 1 write down the boolean expression, for example the first two are AB'C' and A'BC' (where ' denotes NOT) - there are two others. Then in your truth table put a 1 where the conditions are true, for example the above first of the two above expressions will have a 1 where AB = 10 and C = 0 (i.e. AB'C') and the other will have 1 where AB = 01 and C = 0 (i.e. A'BC').

Clearer?

Dave

#### infinitig35

Joined Mar 3, 2008
25
Wow Dave, really appreciate all your help. I think I can figure out the answers from what you've provided me. Again, thanks alot.

Nhat

#### infinitig35

Joined Mar 3, 2008
25
Hey Dave, I have just 1 more question. What is one method of changing a count up type of asynchronous counter to a count down type of asynchronous conter?
This should be the last one. Thanks alot Dave.

Nhat