Difference between PLA and PAL

PLA and PAL are two types of Programmable Logic Devices (PLD) that are utilized to design combination logic and sequential logic. The main difference between these methods is that the PLA has a programmable array of OR and AND gates, whereas the PAL consists of a programmable array of AND gates but a fixed array of OR gates. PLDs also offer a simple and flexible approach to creating logic circuits, with the ability to increase the number of functions. These all methods are also used in IC.

In this article, you will learn about the difference between the PLA and PAL. But before discussing the differences, you must know about the PLA and PAL.

What is PLA?

PLA is an abbreviation for "Programmable Logic Array". It displays the boolean function in the SOP (Sum of Products) format. The PLA includes NOT, AND, and OR gates that are built into the chip. Each and every input is passed through a NOT gate, which makes every input and its complement available to each AND gate. Each AND gate's output is given to every OR gate. Finally, the OR gate output generates chip output.

PLA allows you to program the connections to AND and OR gates, and PLA is thought to be more expensive and difficult than PAL. The two production methods may be utilized for PLA to boost programming ease. In this method, each connection is created via a fuse at each junction point, where the undesirable links may be eliminated by blowing the fuses. In the latter method, connections are made during the fabrication process with the aid of a suitable mask made for a particular interconnection pattern.

Applications of PLA

There are various applications of PLA. Some main applications of PLA are as follows:

1. It is utilized as a counter.
2. It is utilized as a decoder.
3. It is utilized to give control over the datapath.
4. It is utilized as a BUS interface in programming Input/Output.

What is PAL?

PAL is an abbreviation for "Programmable Array Logic". It is a PLD (Programmable Logic Device) circuit that functions likewise to the PLA. Unlike PLA, PAL utilizes programmable AND gates but fixed OR gates. It uses two straightforward functions, where the amount of linked AND gates to each OR gate determines the maximum number of product terms that may be formed in the SOP representation of the function. Even though the AND gates are always linked to the OR gates, the resulting product term is not shared with the output functions.

PLDs are designed to incorporate complex boolean logic into a single chip. As a result, unreliable wiring is eliminated, logic design is avoided, and power consumption is minimized.

Benefits of the PAL

There are various benefits of the PAL. Some main benefits of the PAL are as follows:

1. It is highly secure.
2. It is highly flexible to design.
3. It is highly efficient.
4. It is more reliable than others.
5. It needs low power consumption to work.
6. Its production cost is low than PLA.

Key Differences between PLA and PAL

There are various key differences between PLA and PAL. Some of the key differences between PLA and PAL are as follows:

1. The PLA is a programmable logic device (PLD) with two levels of AND and OR gates. In contrast, PAL only has a fixed OR gate and a programmable AND gate.
2. PAL works faster than PLA. In contrast, PLA works slower than PAL.
3. The PLA complexity is high than PAL. In contrast, the PAL complexity is less than PLA.
4. The speed of PLA is slow. In contrast, the speed of PAL is high.
5. PLA is more expensive than PAL. In contrast, PAL is less expensive than PLA.
6. The PLA is more flexible as compared to PAL. In contrast, PAL is less flexible than PLA.
7. The PAL is easier to produce and more easily available when it comes to availability. In contrast, the PLA is complex to available.
8. PLA has a limited amount of functions implemented. On the other hand, PAL has a huge number of functions implemented.

Head-to-head comparison between PLA and PAL

Here, you will learn the head-to-head comparisons between PLA and PAL. The main differences between PLA and PAL are as follows:

Conclusion

PLA and PAL are both the PLD (Programmable Logic Devices), where PLA is more versatile and flexible than PAL. However, programmable array logic may easily create a combinational logic circuit.