# gray to (7 2 -1 -3) only with 4to1 MUX

Discussion in 'Homework Help' started by Bogdann, Aug 1, 2012.

1. ### Bogdann Thread Starter New Member

Jul 31, 2012
5
1
Hello
I need to implement this conversion of gray code to (7 2 -1-3)code using only 4to1 Multiplexers.

here are the codes codes:

EDIT: seams like copu-paste from excel wont work i ll update this when i come back at home ...
just ignore this thing that should have been nice table

gray 7 2 -1 -3 w x y z f1 f2 f3 f4 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 1 1 0 2 0 0 1 1 0 1 0 0 3 0 0 1 0 1 0 1 1 4 0 1 1 0 1 0 0 1 5 0 1 1 1 1 1 1 1 6 0 1 0 1 1 0 1 0 7 0 1 0 0 1 0 0 0 8 1 1 0 0 1 1 1 0 9 1 1 0 1 1 1 0 0 10 1 1 1 1 x x x x 11 1 1 1 0 x x x x 12 1 0 1 0 x x x x 13 1 0 1 1 x x x x 14 1 0 0 1 x x x x 15 1 0 0 0 x x x x

k-maps:

f1=yzx'+x+w
Wx\yz
00
01
11
10
00

1

01
1
1
1
1
11
x
x
x
X
10
1
1

x

f2=yz'x'+y'z+w
Wx\yz
00
01
11
10
00

1

1
01

1

11
x
x
x
X
10
1
1
x
x

etc...

Now i am not sure if this k-maps are ok, but if we assume they are ok
what is the next step? I tried with shannons theorem but i cant get this right.

It ll be really nice if someone can help me with implementing at least one function.

2. ### WBahn Moderator

Mar 31, 2012
18,079
4,917
Yeah, you're gong to have to format it better. But, also, you need to explain what a 7 2 -1 -3 code is. Are these the weightings on the bits in a four bit integer? If so, then your values run from -4 to +9. You need to define how the gray code vectors (which don't have any intrinsic value) are mapped to values in this range.