Basic Difference Between Programmable Array Logic (PAL) and Programmable Logic Array (PLA)

Programmable logic array (PLA) and programmable array logic (PAL) are generally known as programmable logic devices (PLDs) that have programmable AND array, but with a difference in which one has an additional fixed OR array while the other has an additional programmable OR array.

But what is a programmable logic device?

Programmable logic device (PLD) can be thought of as a blank slate device that can be programmed or reprogrammed depending on the type to perform a logical operation or function.


Programmable here does not denote programming in C or Python, but it is a way of controlling logic circuits so that logical operations can be performed.

PAL is said to be a PLD with a programmable AND array and a fixed OR array.

programmable array logic PAL


You can easily recall this from the fact that A is between P-A-L which means the AND is programmable but the L outside designate that it has a fixed OR array. If you can recall this, then PLA will be easier.

PLA is said to be a PLD with a programmable AND array and a programmable OR array.

programmable logic array PLA

Difference between PAL and PLA

  1. PAL denotes programmable array logic, while PLA denotes programmable logic array.
  2. While PLA is flexible but not simpler than PAL in terms of structure as it contains programmable AND followed by programmable OR array.
  3. The cost of PAL is low compared to PLA
  4. PAL is more commonly used than PLA
  5. PAL speed is higher than the speed of PLA