did anyone ever take Binary Logic/Computer Organization???

[tribal]

having problems with prime implicants. i dont understand how to reduce variables on a 4x4 k-map thru essential prime implicant selection. i got midterm fri, need help!!

[thehacker]

iiiiiiiiick

sorry man.

i graduated computer science

but i promptly purged all that

useless shit upon leaving.

GOOD LUCK!!!

[dialectics]

OK if you want to reduce a 4x4 karnaugh map here's what you've got to do

(i may be rusty on the details because i haven't done this in years)

lets say for example you have the following:

\yz 00 01 11 10

w

x

_________

00 | 1 | 1 | 1 | 1 |

-----------------

01 | 0 | 0 | 1 | 0 |

-----------------

11 | 1 | 1 | 0 | 0 |

-------------------

10 | 1 | 1 |0 | 1 |

-------------------

let's build what this equation is:

w'x'y'z' + w'x'y'z + w'x'yz + w'x'yz' +

w'xyz + wxy'z' + wxy'z + wx'y'z' + wx'y'z + wx'yz'

this equation can be seriously reduced.

take a look at the top line - notice that there are 4 1's in a row. this means that if w and x are both 0, then the output is 1 no matter what y and z are.

so you can reduce this equation to

w'x' + w'xyz + wxy'z' + wxy'z + wx'y'z' + wx'y'z + wx'yz'

next take a look at the group of 4 1's on the lower left hand corner.

you can see that if w is 1 and y is 0 then the equation will always turn out to be 1. So lets reduce this equation to:

w'x' + wy' + w'xyz + wx'yz'

Now if you'll notice that there are a pair of ones next to each other in the third column on the 1st and 2nd rows.

that pair tell you that if w is 0 and y and z are both 1, it doesn't matter what x is. So you can reduce the equation to:

w'x' + wy' + w'yz + wx'yz'

Now there are no more pairs, squares, columns or rows that we didn't cover so this equation is reduced as far as it's ever gonna go.

good luck on your exam!!!!

rob

[thehacker]

Originally posted by dialectics

OK if you want to reduce a 4x4 karnaugh map here's what you've got to do

***bows down at your feet in worship***

[dialectics]

(blushes)

[teklord310]

Yeah I think dialectics has it straight. I did K-Maps in Digital Logic Design since i'm a computer engineer and never ever want to see them again. What a pain in my ass. Good luck to you. I have two exams tommorow.... Linear Systems & Signals and Programming Methodology 2. I'm gonna get butt raped, but I can always hope for the best. good luck!

[dialectics]

is zoran gajik still teaching linear systems? has he fucking finished his book already? when i took that class he hadn't published it yet so we all a binder with a draft of it. it was so poorly edited that every week he gave out a sheet of paper with corrections - and THOSE had errors in them.

i hated that class. it was at 8:10am.

i never took pm2 because i did a dual major in comp sci and got out of it. fucking engineers can't program anyway.

peaz,

rob

[tribal]

dialectics, thanx a mil buddy, im working graveyard now at banc of america, have a whole day of school thur, dont know how im gona get ready for this midterm, but youve helped a LOT, thanx man!!! the only thing is, i dont see how prime implicants help when reducing terms. and so if i find the prime implicants and essential prime implicants of a function, all i do is write down the e.p.implicates + one prime imp.? is that the logic? this is fucking confusing. i had enough shit dealing with binary division and multiplication, this is a hemroid.

[trance604]

Did this last semester...when youre done circling all your groups of 1's or 0's if doing product of sums...look at which circles have 1's hanging out that are not b eing circled by another circle. those entire expressions (circled) are your prime implicants.

prime implicants are used to write a simpler expression.

[thehacker]

Originally posted by dialectics

fucking engineers can't program anyway.

noooo. really? i hadn't noticed!