# Logarithm

#### serial2222

Joined Dec 27, 2014
9
hi friends
i have problem with logic works
i need Logarithm circuit with "logic works"
can someone help me????
plzzzzzzzz

#### WBahn

Joined Mar 31, 2012
28,485
First, what kind of logarithm circuit are you talking about? Analog, digital, ...?

This is not the Homework Done For You forum. You need to show YOUR best attempt to solve YOUR homework problem. We will then help guide you along the path to the solution if we can.

#### serial2222

Joined Dec 27, 2014
9
First, what kind of logarithm circuit are you talking about? Analog, digital, ...?

This is not the Homework Done For You forum. You need to show YOUR best attempt to solve YOUR homework problem. We will then help guide you along the path to the solution if we can.
i exactly dont know what kind ? analog or digital?
but i not one kind electric circuit diagram can be design with logic work
like this : http://t0.gstatic.com/images?q=tbn:ANd9GcSHOVeCKma5-JakuSBwuYzJ0m3N7vFPyE-Qq4Lm494X1M5c0IMo
but i say i become dizzy (
help me plzzzzzzz

#### WBahn

Joined Mar 31, 2012
28,485
So what, exactly, is the assignment?

#### serial2222

Joined Dec 27, 2014
9
Log 2 (A) + Log 2 (B )

#### WBahn

Joined Mar 31, 2012
28,485
How are A and B represented?

#### serial2222

Joined Dec 27, 2014
9
in digital mode

#### WBahn

Joined Mar 31, 2012
28,485
Again, how are the values A and B represented? Unsigned integers? Two-complement? IEEE Floating point?

What, exactly, is the assignment?

#### serial2222

Joined Dec 27, 2014
9
two - comlement ==> true table ===> karno ===> equation ===> circuit

#### WBahn

Joined Mar 31, 2012
28,485
Okay. So focus on taking the base-2 logarithm of a two's complement number.

What representation is the output supposed to be in?

#### serial2222

Joined Dec 27, 2014
9
yes.
in seven segment

#### WBahn

Joined Mar 31, 2012
28,485
yes.
in seven segment
"seven segment" is not a representation format. A representation format is something like "unsigned binary", "twos-complement", "IEEE-754 single-precision floating point", "fixed point".

#### serial2222

Joined Dec 27, 2014
9
oh ye
twos-complement and show result in seven segment

#### WBahn

Joined Mar 31, 2012
28,485
Okay.

So what should the output of your circuit be if the input is 5? What should be displayed?

What if the input is -12?

#### serial2222

Joined Dec 27, 2014
9
shows error

#### WBahn

Joined Mar 31, 2012
28,485
shows error
For both cases?

How does it show an error?

What values of input should it NOT show an error for?

#### serial2222

Joined Dec 27, 2014
9

more intricacy accord

#### WBahn

Joined Mar 31, 2012
28,485

more intricacy accord
I don't understand what you are saying here. I suspect it is just a language barrier problem, so try rephrasing.

You said that if you have an input value of 5 that the output should show error. So in response to that I have two questions:

Why should the base-2 logarithm of 5 produce an error?

How will you show an error on your 7-segment displays?

In addition, I asked you to describe what input values (at least give an example or two) should not produce an error and what the output values should then be.