FPGAs

FPGAs
What are FPGAs?
FPGA stands for Field Programmable Gate Array. They are small semiconductor logic chips known as integrated circuits, or ICs for short. FPGAs are built from one basic logic cell, duplicated hundreds of times.
What do they consist of?
They consist of a configurable logic block, programmable switch matrix, I/O blocks and Interconnects.
Configurable Logic Block
CLB consist of lookup tables (LUTs), flip flops and multiplexers. They are used to implement complex design functions and synchronise the code on the FPGA.
Programmable Switch Matrix
A programmable switch matrix (PSM) is used to control the interconnections between the configurable logic blocks and the input / output blocks. The programmable switch matrix connects each block according to the program code and has switch elements that have six pass transistors inside.
I/O Blocks
I/O blocks are pins that can be programmed as an input pins, output pins or both.
Interconnects
Interconnects carry signals via wires to connect inputs and outputs to logic blocks.
Features and Benefits
FPGA functionality can easily be developed upon every power-up of the device. Design engineers can enable changes by downloading new software configuration files into the device and test the changes.
How do FPGAs differ from CPLDs?
CPLDs stand for complex programmable logic devices. They are used to implement complex combinational or sequential circuits. They are made up of logic array blocks, programmable interconnects and I/O blocks.
FPGA Applications
They are found in many applications such as radar systems, military hardware, medical devices and telecommunication technology. Their reprogrammable nature means FPGAs are suitable for a wide range of solutions. They are able to be any digital circuit, depending on the number of logic blocks it contains. Engineers often use FPGAs in prototype development and specialise designed integrated circuits (ICs).