CPLDs, an acronym for complex programmable logic devices, are integrated circuits designed for the implementation of sequential or complex combinational circuits, such as mobile phones. They comprise necessary and functional blocks, such as logic array blocks, I/O blocks, programmable interconnects within a single chip, and integrated wiring to attach the circuit blocks.
Components of CPLDs
As mentioned above, these integrated circuits consist of blocks with the following main functions:
- Logic Array Blocks – Comprised of macrocells, metrics (inward/non-inward), and flip flop support integrated circuits to implement sequential circuits.
- Programmable Interconnects – Designed to disperse signals between array blocks.
- I/O Blocks - The input and output pins on I/O blocks can be programmed in either direction.
What are the Key Benefits and Specifications of CPLDs?
CPLDs offer the following features and advantages.
- They do not require ROMs to function at startup.
- Feature non-volatile configuration memory.
- There are usually thousands to tens of thousands of gates to choose from.
- They are economical and user-friendly.
- Feature on-chip non-volatile memory.
- Simple and easy to use.
- They require low power.
How are CPLDs Different from FPGAs?
The main difference between these two digital logic chips lies in their architectures. CPLDs are less flexible due to their restrictive structure, whereas FPGAs (Field Programmable Gate Arrays) are dominant due to their large interconnect. An FPGA is a miniature semiconductor IC comprising hundreds of duplicated logic cells suitable for military, radar systems, medical, and telecommunications applications.
What are the Typical Environments and Applications of CPLDs (Complex Programmable Logic Devices)?
CPLDs are widely found in various areas to perform numerous applications, such as:
- A field-programmable gate array to load configuration data from non-volatile memory.
- Highly demanding applications areas for efficient performance and critical control applications.
- Boot loader applications in digital designs.
- Small design applications as address decoding.
- Portable equipment, such as mobile phones and tablets.
