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2 October 2020

Difference between PAL and PLA

PLA ad PLA are the types of programmable logic devices (PLD) that are used to design combination logic together with sequential logic. The main significant difference between PAL and PLA is PAL ca easily produce a combination logic circuit. While in PLA is more flexile ad adaptable than PAL. So here this article gives the main key difference between PAL and PLA to better understand this topic.

Definition of PLA

PLA Stands for the programmable logic array, which presents the boolean function in the SOP form. The PLA contains  AND and OR and NOT gates fabricated on the chip. It passes every input by a NOT gate which makes each input and its complement available to every OR gate. The OR gate output produces chip output. So, this is how suitable connections are made to employ the sum of product (SOP) expressions function.

Definition of PAL

PAL stands for programmable array logic, it is also a PLD circuit that works similarly to the PLA. PAL employs the programmable AND gates but they are fixed with OR gates, unlike PLA. It implements two simple functions where the number of links AND gate to each OR gate specifies the maximum number of product terms that can be generated in the sum of product representation of the particular function. While the AND gates are perpetually connected to the OR gates, which signifies that the produced product terms is not shared with the output function.

Difference between PAL and PLA:

  • PAL stands for programmable array logic, while PLA stands for a programmable logic array.
  • The construction of PAL can be done using a programmable collection of AND & OR gates. The construction of PLA can be done using the programmable collection of AND & fixed collection of using OR gates.
  • The flexibility of PAL programming is more, while PLA is less flexible.
  • The availability of PAL is less prolific, The availability of PLA is more.
  • The cost of a PAL is expensive, while the cost of PLA is a middle range.
  • The number of functions implemented is PAL is large, The number of functions implemented is limited.
  • PAL more used than PLA, PLA is less used than PAL.
  • The speed of  PAL is too slow, but the speed of PLA is high. 
  • PAL complexity is high, The complexity of PLA is high.

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