An application-specific integrated circuit (ASIC) is a compactly packaged electronic circuit intended to simplify the overall circuit design. In some cases it also prevents reverse engineering of an existing product. For instance, many products use a single special-purpose chip to control the product. Almost all gadgets, like computers, cell phones, and other digital devices will be using at least one ASIC. This circuit differs significantly from a general-purpose integrated circuit (IC).
Also known as microchip, the IC was first introduced to minimize the component count in a circuit board. If the circuit previously used a dozen transistors with two-dozen resistors and capacitors, the IC is used to replace most of these parts. The result is a certain degree of miniaturization that has become the first of a series of ever-increasing density of components in an IC. Modern microprocessors, for instance, contain over a million transistors in a space less than a square inch.
The application-specific integrated circuit is often used in complex circuit applications. For instance, in the personal computer with a simple graphics adapter card, it may not be possible to successfully install a graphic-intensive game. The game installer may be expecting a compatible graphics accelerator card (GAC), which contains an ASIC that is capable of implementing high-level graphics commands that an ordinary graphics adapter will not be able to interpret. An ASIC may be able to draw standard shapes at the same time in different locations on the screen. This feature is required to generate images rapidly enough to look real.
In data communications, the application-specific integrated circuit can be used in computers, hubs, switches, and routers. The network interface card (NIC) uses a customized chip, an ASIC that handles the physical and data link layer requirements of the local network segment. The ASIC in the NIC is responsible for the physical behavior of the NIC. For instance, an Ethernet adapter will have an application-specific integrated circuit that is able to handle tasks such as packet collision detection and retransmission as needed. If the NIC is a token-ring type, the ASIC then awaits the reception of a flag packet known as a token before it attempts to transmit into the network.
Higher-density semiconductor chips are often preferred in electronics manufacturing. This results in newer products with general-purpose chips and application-specific integrated circuits with lower parts count and smaller sizes or footprints. An exception twill be high-power or special-application semiconductors that require separate mounting from the rest of the components on the board. If the general-purpose portions of the circuit can be integrated into a smaller package, the result is usually an application-specific integrated circuit.
