What is the difference between ASIC and FPGA

1. Concept difference

ASIC (Application Specific Integrated Circuit) is an IC that has been designed with design in mind.

Application Specific Integrated Circuit.png

FPGA (Field Programmable Gate Array) is also an IC. As the name implies, engineers can reprogram FPGAs as long as they have the right tools and proper professional foundation.

2. Difference in development process

FPGA development is to use EDA tools such as HDL, quartus, vivado, etc. to reconfigure the functions of the chip, and ASICs usually have less reconfiguration capabilities.

Basically, ASICs are designed based on standard units, and Place & Route is also required. When there are any problems with the chip, you must re-slide again until you reach the desired function and performance. The ASIC design process is very expensive and takes at least a few months to complete.

ASIC can no longer be changed after leaving the production line. This is why designers need to fully ensure that the design is correct before mass production. Engineers can take advantage of FPGA reconfiguration to perform prototype verification of ASICs so that they can fully test the design in the real world before sending it to the foundry.

FPGA is a lot of prefabricated gates and flip-flops, with programmable interconnect features. You can use these basic modules to configure any logical function you want. If there is an error, it can be reprogrammed within a few seconds instead of months. However, in FPGAs, sometimes additional hardware overhead is required to make the correct connections.

3. Cost difference

ASIC has a great advantage in terms of repetitive cost, because very little material is wasted in the design. For FPGA, there are always a lot of hardware resources wasted. This means that the repetitive cost of FPGAs is usually higher than the repetitive cost of similar ASICs.

Although the repetitive cost of ASIC is very low, its non-repetitive cost is relatively high and usually reaches millions. Because it is non-repetitive, the cost of each IC decreases as the volume increases.

Therefore, after mass production of ASIC to a certain amount, using ASIC can be cheaper than using FPGA. Compared with FPGA, ASIC has great advantages in power consumption, performance, size and cost.