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ASIC anyone?

5 mins read

​Has the world got the taste again for ASICs? Socionext discusses the advantages associated with this technology

ASICs – Application-Specific Integrated Circuits – came about in the 1980s, as decreasing costs for IC technology, new design methods and powerful new software tools emerged.

Previously, designing semiconductors was the exclusive domain of a number of very specialised semiconductor manufacturers, who had the means to set up semiconductor production as well as the technical expertise in IC technology, production and design.

In subsequent years, the semiconductor industry developed rapidly and with the launch of hardware description languages as well as logic synthesis enabled the now standard complex circuits comprising several million logic gates to be implemented on an ASIC.

CMOS (Complementary Metal Oxide Semiconductor), the dominant semiconductor technology, was also undergoing continual miniaturisation resulting in increased integration density ao that by the mid-1980s, CMOS technologies enabled minimal structures of 1um to be implemented on an IC. Today’s CMOS can offer minimal structure sizes of 7nm.

Nevertheless, there are signs that the speed of miniaturisation is slowing. The minimal dimensions of current transistors in the single-digit nm range indicate that the simple, planar CMOS production process no longer functions at every point. Transistors have now become so small that physical effects such can dominate and impair transistor performance.

Manufacturers compensate for this with innovative new production methods and technological innovations. From 16nm, for example, all mainstream CMOS processes work with FinFET transistors, which reduce the short-channel effect in CMOS. From 7nm, a very short-waved ultraviolet light (EUV) is also used with a wave length of 13.5nm to illuminate the masks.

As a result, the costs for the respective latest semiconductor technology have continually risen in recent years and ASIC customers have started to feel the impact of increased development costs.

In fact, developing ASICs for the latest semiconductor technology only makes economic sense if high unit volumes are expected. Of course, this also means that an ASIC with the latest technology can be used by significantly fewer customers than was previously the case. As a result, the ASIC industry has undergone a number of significant changes in the past decade. The number of ASIC providers has fallen and it appeared that ASICs would only remain of interest to a minority of users. However, things appear to be changing.

Why? Many applications are currently evolving in a direction which is predestined for ASIC, as they are so innovative or the requirements are so specific that there are no suitable standard products available.

The automotive market is set to become one of the largest ASIC growth markets. The amount of electrical components installed in cars is increasing significantly driven by demand for driverless cars, or at least automated advanced driver assist systems (ADAS), which is triggering rapid developments in the field of sensors (radar, lidar, optical sensors) and in artificial intelligence.

Consumers now expect a variety of communication, information and entertainment equipment in their vehicles such as smartphone connectivity, displaying on-board and environmental data as well as in-car entertainment.

Demand for wireless communication, between different road users and between vehicles and the road is also increasing. All in all, these applications will make the automotive market one of the key drivers of ASIC technology in coming years.

Artificial Intelligence

Artificial intelligence is now being used in various products, such as digital home assistants, smartphones and robot vacuum cleaners.

It is also set to play an even greater role in the automated processing of video data in real time, for example in the field of security monitoring. These systems usually only have a limited power supply and are not allowed to get too hot as they are kept in encapsulated housing. As a result, efficiency (i.e. processing power per mW) plays a significant role here – giving ASICs a significant market opportunity.

The Internet of Things has been identified as a growth driver and today there is a clear trend, where more and more devices are being upgraded using smart electronics and connected in networks using either wired or wireless technology. Low power is a particularly important issue here. Thanks to the integration of an RF and digital part on an ASIC, highly efficient IoT implementations are now possible.

In the field of production automation, a quiet revolution has taken place. Industry 4.0 is based on the digitalisation of production. This field is diverse and offers a wide range of ASIC applications such as PLC control systems, encoders and servos as well as human-machine interfaces.

Alongside new markets, ASIC technology is also being driven by the broad selection of semiconductor processes that are now available. It does not make sense to select the latest technology for all products. Instead, it is important to tailor the process to the application.

If a customer wants a purely digital ASIC with several million logic gates and fast interfaces such as DDR5, a 7nm ASIC is likely be a good choice. For the above-mentioned applications, however, other technology drivers are often more important. If a customer wants to implement a flash memory on the ASIC, for example, it generally makes sense to choose “older” technologies up to approx. 40nm, as flash is currently only available for these.

Furthermore, the integration of the digital part, the analogue part and the RF part is becoming increasingly important. This also has a major influence on the selected technology. Today, foundries offer RF and mixed signal extensions for their CMOS processes, which can be used to implement special semiconductor structures and passive components for RF and analogue applications. RF and analogue circuits do not necessarily benefit from minimum transistor geometries. As a result, larger CMOS process nodes of 180nm to 40nm are generally chosen for these kinds of applications.

Also, an ASIC does not need to be developed completely from scratch. The market for IP blocks is very extensive today and an ASIC user can purchase numerous standard functionalities as intellectual property (IP) and then focus exclusively on developing their own “user logic”. The use of IP ultimately saves development costs and time and reduces the design risk.

ASICs are considered a benefit for applications that require a high integration density. The widest range of functions (digital, analogue, RF) can be implemented on a single ASIC. This can reduce the bill of materials and ASICs always have lower unit costs compared with field-programmable gate arrays (FPGAs). The user naturally pays for this in the form of increased development effort and costs.

Developing a ASIC therefore makes sense for larger volumes, where the savings in unit price compensate for the initial development costs.

However, some customers choose ASIC for entirely different reasons. User-specific functionality can be implemented by definition in an ASIC. These may be functions that are not available in a certain form on the market or which enhance the unique selling points (USPs) of an in-house product. An ASIC can therefore contribute towards clearly differentiating a product from competitors.

The use of an ASIC in their product also offers customers a certain degree of security that their product cannot be easily copied. Since ASICs are customer specific by definition, they cannot be simply purchased on the open market, which deters potential copycats.

There is also the option of using protective measures to prevent an ASIC from being reverse engineered, thus making it impossible, or extremely difficult, to copy the ASIC. Since product piracy has been on the rise for years, this is a key factor for some customers in developing an ASIC.

Today, ASICs maintain an important position in the semiconductor market. Increased development costs do not inevitably mean that ASIC is only for the big players. A variety of semiconductor technologies are now available which allow affordable designs.

Furthermore, in recent years, new markets have been formed which are predestined for the use of ASIC component