What Is a PLD (Programmable Logic Device)?
A PLD (programmable logic device) is an integrated circuit that allows the user to define and modify the internal logic circuitry after manufacturing.
Compared to ASICs (application-specific integrated circuits) and ASSPs (application-specific standard products), PLDs offer greater design flexibility and lower cost. For this reason, PLDs are widely used in a variety of electronic devices.
There are various types of PLDs, including FPGAs (field programmable gate arrays) and CPLDs (complex programmable logic devices). A CPLD has fewer gate arrays than an FPGA but is less expensive.
Uses of PLDs (Programmable Logic Device)
PLDs are widely used in a variety of industries due to their flexibility and efficiency. Specific use cases include:
1. Telecommunications Industry
In the telecommunications industry, PLDs are used for rapid hardware redesign to adapt to new communication standards, thus speeding up time-to-market.
2. Automotive Industry
The automotive industry uses PLDs to shorten development cycles for advanced driver assistance systems and in-car experiences and to meet safety standards in hybrid and electric vehicles.
3. Consumer Electronics Industry
PLDs are used in home appliances to support various video standards and to add AI functions.
Principle of PLDs (Programmable Logic Devices)
The principles of PLDs involve understanding their internal structure and hardware description language (HDL).
1. Internal Structure of PLDs
The basic internal structure of a PLD consists of programmable logic gates and connections. Logic gates perform specific logical operations (AND, OR, etc.) on input signals.
Some PLDs range from basic gate-level devices, like Programmable Array Logic (PALs), to more advanced devices like CPLDs and FPGAs.
2. Hardware Description Language
HDLs, such as VHDL and Verilog, are used to program PLDs, allowing precise descriptions of hardware behavior and its simulation.
Types of PLDs (Programmable Logic Device)
PLDs are classified into various types based on their structure and programmability, including:
1. PLA (Programmable Logic Array)
A PLA is a basic PLD with a programmable array of logic gates.
2. PAL (Programmable Array Logic)
PALs have a programmable AND array and a fixed OR array, suitable for simple circuits.
3. CPLD (Complex Programmable Logic Device)
CPLDs, with more gates than PALs, are suitable for larger digital systems.
4. FPGA (Field Programmable Gate Arrays)
FPGAs are advanced PLDs with up to millions of programmable logic gates, used for large digital systems.