# Truth table to Logic gates converter

#### chroncile

Joined Mar 27, 2010
13
Are there any programs out there that can convert truth tables to logic gates?

I need to convert this:

DECIMAL INPUTS SEGMENT OUTPUTS
DIGIT D C B A A b c d e f g
0 0 0 0 0 1 1 1 1 1 1 0
1 0 0 0 1 0 1 1 0 0 0 0
2 0 0 1 0 1 1 0 1 1 0 1
3 0 0 1 1 1 1 1 1 0 0 1
4 0 1 0 0 0 1 1 0 0 1 1
5 0 1 0 1 1 0 1 1 0 1 1
6 0 1 1 0 0 0 1 1 1 1 1
7 0 1 1 1 1 1 1 0 0 0 0
8 1 0 0 0 1 1 1 1 1 1 1
9 1 0 0 1 1 1 1 0 0 1 1
10 1 0 1 0 X X X X X X X
11 1 0 1 1 X X X X X X X
12 1 1 0 0 X X X X X X X
13 1 1 0 1 X X X X X X X
14 1 1 1 0 X X X X X X X
15 1 1 1 1 X X X X X X X

#### beenthere

Joined Apr 20, 2004
15,819
There may be, but IC's with internal logic to do that already exist. Grab a data sheet for a 7447 to see how it's done.

#### chroncile

Joined Mar 27, 2010
13
I googled 7447 datasheet, but I couldn't find a logic gate representation; that's what I am suppose to do. The teacher told us to do each segment; use a K-Map to find out the simplified expression for each segment and then group all the segments into one big simplified expression.

D C B A b
0 0 0 0 1
0 0 0 1 1
0 0 1 0 1
0 0 1 1 1
0 1 0 0 1
0 1 0 1 0
0 1 1 0 0
0 1 1 1 1
1 0 0 0 1
1 0 0 1 1
1 0 1 0 X
1 0 1 1 X
1 1 0 0 X
1 1 0 1 X
1 1 1 0 X
1 1 1 1 X

#### chroncile

Joined Mar 27, 2010
13
What do you mean work backwards? I already finished the assignment, but I would still like to know what you mean by working backwards.

Also, is there a program I can use to draw my circuit? I have to draw a copy of the circuit, but it would take me way too long to do it by hand.

Thanks

#### beenthere

Joined Apr 20, 2004
15,819
Work back from each segment. Look for common states shared by two or more segments.

As for schematics, I use my CAD program. Some members use MS Paint.