There is a unique type of IC called the application-specific integrated circuit that is very common in the hardware.
ASICs and FPGAs are types of microchips. For a person who is new to the field of VLSI or hardware design, it is important to understand the difference between ASIC and FPGA.
ASIC vs FPGA
The main difference between ASIC and FPGA is that ASIC is designed for a specific purpose, like the CPU of a mobile phone, whereas FPGA is a microchip that performs many programs for many applications.
ASIC stands for Application Security Integrated Circuit. It is a type of circuit made by engineers for a specific type of application. The cost per production of ASICs is less than which then makes them much more compatible. They have a complex design, and they cannot be reprogrammed.
FPGA are used by engineers in prototypes while designing a product using descriptive languages like VHDL or Verilog. They are useful to use in appliances like vehicles or image processing in security appliances because they can be upgraded from time to time. They have a simple design.
Comparison Table Between ASIC and FPGA
| Parameters of Comparison | ASIC | FPGA |
| Design | ASIC has a more complex design. | FPGS has a simple and faster design. |
| Stages | ASIC needs seven complex stages. | FPGA has simple and faster stages. |
| Reprogramming | ASIC cannot be reprogrammed. | FPGA can be reprogrammed. |
| Performance | ASIC has better performance than FPGA. | FPGA provides lower performance than ASIC. |
| Compatible | ASIC is much compatible with FPGA. | As the cost per production is higher than FPGA, it makes it less compatible than ASIC. |
| Mass production | ASICs are suited for high-volume production. | FPGAs are not suited for high-volume production. |
What is ASIC?
ASIC stands for Application Security Integrated Circuit.
ASIC is an application-based circuit that is designed and manufactured for just one application. It does not allow one to reprogram after it is produced.
It is a chip technology that has various applications. Generally, they are used by engineers. As they cannot be manipulated, the engineers use them for permanent applications, which includes devices like smartphones or computers, etc.
ASICs are not meant for general use. They come in various types like gate arrays, custom designs, etc.
ASICs working depends on the type of ASIC. Like the gate array, ASICs give only one opportunity for customization by manipulating the connections between the transistors. But they perform limited functions. The standard cell ASICs are more customizable than the gate array ASICs. The full custom design ASICs allows one to do full customization using scratch for their own exact specifications.
For example, the CPU in a mobile phone is a type of ASIC.
What is FPGA?
FPGA stands for Field Programmable Gate Array. It is a microprocessor or an encryption unit or graphics card that can be programmed for the purpose.
It is made up of many CLBs (configurable logic blocks). They implement the logic functions. They can also contain silicon blocks for many functions like Block RAM, DSP blocks, etc.
It is a circuit that can be programmed one time or can be reprogrammed many times.
The designs are created using descriptive languages like VHDL or Verilog.
There are two types of classifications done to recognize FPGAs: by the arrangement of the blocks or by the programming language used. There are three types of arrangements of FPGAs: symmetrical arrays, row-based architecture, and hierarchical PLDs.
Symmetrical arrays are made up of rows and columns of logic blocks. Row-based architecture is an arrangement where there is a row of logic blocks and programmable resources. Hierarchical PLD is an arrangement that has a much more typical and complex layout.
There are three types of programming languages used in the FPGAs: SRAM-based FPGAs, anti-fuse-based FPGAs, flash-based FPGAs.
SRAM-based FPGAs use a type of external memory that uses internal flash blocks. The anti-fuse-based FPGAs can only be once programmed. Flash-based FPGAs are used for storage to retain the data when the power is down.
Main Differences Between ASIC and FPGA
- ASIC design flow is much more complex and design-intensive than FPGAs.
- ASICs involve seven stages to get complete in design, whereas the design flow of FPGAs is simple and faster.
- FPGA can be reprogrammed as it performs limited functions, whereas ASIC cannot be reprogrammed.
- ASIC have much better performance and provide more efficiency than FPGA.
- ASICs have more NRE costs than FPGAs.
- ASICs have lower power consumption than FPGAs.
- ASICs are suited for high-volume production, whereas FPGAs are not suited for high-volume production.
- ASICs are used where the applications do not need frequent up-gradation, whereas FPGAs are used when the applications need up-gradation from time to time.
- As the ASIC cannot be altered thus, the designer needs to be sure before making it, especially when making it in bulk, whereas FPGA allows a designer to change and alter things from time to time.
- Cost per production is lower while producing ASIC than FPGA. Thus making ASIC much more compatible than FPGA.
Conclusion
ASICs and FPGAs are types of microchips.
ASICs are used where the applications do not need frequent up-gradation. The engineers who design them needs to take care of everything from reset tree to testing constraints. As the ASIC cannot be altered thus the designer need to be sure before making it, especially when making it in bulk. ASIC has a cost advantage as less waste is produced while producing an ASIC.
FPGAs are used when the applications need up-gradation from time to time. The engineers who design them generally do not need to handle everything. FPGA allows a designer to change and alter things from time to time, so the manufacturers use this as an advantage and take all the types of prototypes with FPGA, and when they are sure, they send out the design to be produced in an ASIC. FPGA uses many types of transistors, thus making the cost higher.
But after analyzing the cost of production with respect to volume, one would find that FPGA becomes cheaper than ASIC when one is produced in lower numbers.
References
- https://ieeexplore.ieee.org/abstract/document/4068926/
- https://www.sciencedirect.com/science/article/pii/S0026269205003927