# Programmable Logic Array (With enable change & Clock Pulse)

#### johnnyblaz

Joined Dec 10, 2015
9
Hello Everyone!!
As far as I know Programmable Logic Arrays (PLAs) are used for implementing combinational circuits & combinational circuits do not operate on clock pulse.Given the homework problem statement I don't understand how to design a pla that makes connections according to the value of S . I'm a complete newbie on this topic. Please explain the problem statement and suggest a method to implement the problem. Any kind of help would be greatly appreciated. Thanks!!

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#### AnalogKid

Joined Aug 1, 2013
11,027
That is not a "complete newbie" level question, so I'm wondering why you have it if the course material has not prepared you for it. Separate from that, the term "PLA" is not nearly descriptive enough to know what the device features are (inputs, outputs, registers, macrocells, etc.). Need a lot more information.

ak

#### bertus

Joined Apr 5, 2008
22,275
Hello,

For the ones who do not want to open the PDF, here is the text from it:

Programmable PLA
ProblemSpending a lot of time with a 3 input, 3 product term and 2 output PLA,
the designers finally found that there ever changing design needs a dynamically
programmable PLA, such that the connections can be turned on and off by inputs
to the circuit. A 3x3x2 PLA has 26 connections that can be turned on or off. So
apart from the normal A, B, C inputs and F1 & F2 output, it has 7 additional inputs
E, S & N0...N4. When E (enable) is high, the connection numbered N (N0...N4) is
turned on or off according to the value of S. You can number the connections in
any
order. Don’t take any action if a number above 25 is available in N i.e. a wrong
input.
Input: Clock Pulse CP, PLA Inputs A, B, C, Enable change E, Connection number
N0...N4, Set connection S
Output: PLA Outputs F1, F2
Bertus

#### johnnyblaz

Joined Dec 10, 2015
9
That is not a "complete newbie" level question, so I'm wondering why you have it if the course material has not prepared you for it. Separate from that, the term "PLA" is not nearly descriptive enough to know what the device features are (inputs, outputs, registers, macrocells, etc.). Need a lot more information.

ak
It was assigned as a DIY project. And I can't find any information on designing pla with the required inputs. Need help!!

#### AnalogKid

Joined Aug 1, 2013
11,027
Need part number!!

#### JohnInTX

Joined Jun 26, 2012
4,787
Thread moved to Homework Help. Welcome to AAC!

#### sailorjoe

Joined Jun 4, 2013
365
JohnnyB, what have you done so far to get started on this?