What is program logic array

Sign up. Term of the Day. Best of Techopedia weekly. News and Special Offers occasional. Techopedia Explains Programmable Logic Array PLA A programmable logic array is designed such that a number of different logical functions can be combined as a sum-of-product or product-of-sum form. Share this Term. Tech moves fast! Stay ahead of the curve with Techopedia! Hence, apply those required product terms to each OR gate as inputs.

Therefore, the outputs of PAL will be in the form of sum of products form. The given two functions are in sum of products form. There are two product terms present in each Boolean function. The corresponding PAL is shown in the following figure. The programmable AND gates have the access of both normal and complemented inputs of variables.

So, program only the required literals in order to generate one product term by each AND gate. Here, the inputs of OR gates are of fixed type. So, the necessary product terms are connected to inputs of each OR gate. So that the OR gates produce the respective Boolean functions.

Hence, it is the most flexible PLD. The block diagram of PLA is shown in the following figure. Here, the inputs of OR gates are also programmable. So, we can program any number of required product terms, since all the outputs of AND gates are applied as inputs to each OR gate. The corresponding PLA is shown in the following figure. All these product terms are available at the inputs of each programmable OR gate. But, only program the required product terms in order to produce the respective Boolean functions by each OR gate.

Gowthami Swarna. So, AND matrix is used to give product terms as output. Basically each AND gate in the circuit provides the product of the terms present in the inverted and non-inverted form at its input. OR matrix : An OR logic gate is designed to perform addition.

Thus the OR matrix provides the addition of the input as the output. Now the question arises how can we implement any boolean function using PLA? So, let us now proceed towards the same. Now, firstly we need to simplify the above boolean expression. It is to be noted here that by simplifying, the number of product terms can be reduced to minimum.

Thereby, producing less complex circuit. Now, as we have already discussed that the number of input buffer will be equal to the total number of variables. And here we are having 3 variables. So, we will have 3 separate input buffer, one for each variable.