ASIC or Custom SoC – What’s the difference?
The benefits of using custom chips at a system level have long been recognized. This approach enables optimization of feature set, performance, power consumption and final chip cost compared to both the use of ‘off-the-shelf’ standard products or FPGAs. It also enables a higher level of integration, with a consequent reduction in both space requirements and overall BOM cost.
The added value and benefits offered by custom chip design must of course be set against the development cost, including the NRE charges required by the custom chip provider for items such as chip implementation, IP access fees and mask charges amongst others.
Traditionally, such custom chips have been described as Application-Specific ICs (or ASICs), so how does this differ from a Custom SoC?
There are two key aspects to consider here. Firstly, the design specification or chip content as well as the interface and design responsibilities between customer and the chip supplier. In a traditional ASIC, the chip design is the responsibility of the customer, based on technology libraries delivered by the chip supplier. The design is delivered to the supplier in the form of a technology specific gate-level description (‘netlist’) or as a higher-level software description (‘RTL’). The chip supplier then handles the conversion of the customer design into a physical chip, including packaging and test of the final product. Each party must take responsibility for its part in the overall design.
ASICs may (and often do) include multiple macro IP blocks supplied by the chip vendor, but do not necessarily include any dedicated CPU functionality. A System-on-Chip solution (by its very definition) is based around a CPU or multiple CPU subsystems and acts as the central processing element in the final system. In addition to the CPU(s), the SoC will also contain any number of other processing units, such as ISP, DSP or GPU as well as other dedicated IP blocks for functions such as high-speed external interfaces.
In order to design an ASIC, customers have to have either a dedicated internal chip design team or at minimum in-house experts to interface to an external design partner. This may be difficult to justify when the number of custom designs required is limited. By comparison a Custom SoC approach offers additional options, with the chip supplier taking more of the design responsibility. This may range from a ‘Platform-based’ approach (where the supplier offers pre-verified subsystems) to a ‘spec-in‘ design where the supplier takes full responsibility for the complete design process.
The Custom SoC approach therefore offers customers the possibility to access their own custom-designed chip with the minimum of design effort and resource on their side, even if they have no in-house chip design expertise. Selecting the right silicon partner becomes even more critical under these circumstances. With almost 40 years of experience in ASIC & Custom SoC design, and its proven ability to handle the most complex of projects based on leading edge process technologies, Socionext is the ideal partner for your custom silicon needs.
Think ASIC/Custom SoC – Think Socionext!