By Neelam Kumar

There’s a revolution in the modern world due to electronic circuits.

Used in complex systems all the way to individual transistors, designing one can be an interesting task.

Manufactured in various fabs all over the world, it is interesting to observe the transition in the number of transistors per die.

The first computers in the 1940s had bigger components, now a single chip can have billions, with sizes shrinking up to a few nanometres.


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Cost per digital IC is decreasing. Formal design involves writing requirements after liasing with customers, writing a technical proposal to meet requirements, then synthesizing on paper a schematic circuit diagram, an abstract one that meets specifications.

The calculation of component values is done, then simulations are performed to verify correctness. A breadboard is prepared, and alterations are done to achieve compliance.

A construction method is chosen, as well as parts and materials decided. The layout and component information is given to draughtspersons and layout and mechanical engineers for prototype production.

A circuit design is verified, a mathematical process involving large-scale simulations. Mock-ups are used to assess appearance and usability.

Commercial design involves documentation, the precise nature differs according to the country in which it is used. This involves a CE, CSA, UL, VDE, BSA etc. depending on the country’s required regulatory norms.

Electronic circuit design also uses different levels of abstraction depending on the complexity of the design task under consideration. The importance of the abstraction level lies in the fact that once design primitives are defined, the problem of extracting the knowledge (rules) is easier.

Digital IC design is to produce components such as microprocessors, FPGAs, memories (RAM, ROM, and flasg) and digital application specific integrated circuits. Digital design focuses on logical correctness, maximizing circuit density, and placing circuits so that clock and timing signals are routed efficiently.

Field-Programmable gate arrays (FPGA) are the modern-day technology for building a breadboard or prototype from standard parts; programmable logic blocks and programmable interconnects allow the same FPGA to be used in many different applications.

Designers of digital ASICs use a hardware description language (HDL), such as Verilog or VHDL, to describe the functionality of ASICs.

Design techniques include standard-cell techniques, gate array, full custom, structured and multi-project wafers. Cell libraries of logical primitives are kept for re-use and further development.

Many organizations including OpenCores are collecting free IP cores like the (supposed free code) movement in software. Soft macros are process independent, while hard ones are process-limited for portability to different manufacturers.

Some manufacturers offer Multi-Project Wafers (MPW) as a method of obtaining low cost prototypes. Often called shuttles, these MPW, containing several designs, run at regular, scheduled intervals on a “cut and go” basis, usually with very little liability on the part of the manufacturer.

There are two different types of ASIC suppliers, IDM(Integrated Device Manufacturer) and fabless. An IDM supplier’s ASIC product is based in large part on proprietary technology such as design tools, IP, packaging, and usually although not necessarily the process technology.Eg. Motorola

Fabless ASIC suppliers rely almost exclusively on outside suppliers for their technology. eg. Qualcomm, Xilinx








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