Integrated circuit design, or IC design, is a subset of electronics engineering, encompassing the particular logic and circuit design techniques required to design integrated circuits, or ICs. ICs consist of miniaturized electronic components built into an electrical network on a monolithic semiconductor substrate by photolithography.
IC design can be divided into the broad categories of digital and analog IC design. Digital IC design is to produce components such as microprocessors, FPGAs, memories (RAM, ROM, and flash) and digital ASICs. Digital design focuses on logical correctness, maximizing circuit density, and placing circuits so that clock and timing signals are routed efficiently. Analog IC design also has specializations in power IC design and RF IC design. Analog IC design is used in the design of op-amps, linear regulators, phase locked loops, oscillators and active filters. Analog design is more concerned with the physics of the semiconductor devices such as gain, matching, power dissipation, and resistance. Fidelity of analog signal amplification and filtering is usually critical and as a result, analog ICs use larger area active devices than digital designs and are usually less dense in circuitry.
Before Designing a Chip? Need to Brain Storm
What market is the Chip targeted for?
What are the Protocols involved in the Chip?
What is going to be our Processor/Bus Architectures?
What is the power/IR-drop/timing/area/yield targets and how to budget it in the Chip?
What is the process in which the Chip is going to be manufactured?
What are the various third-party IP's/Memory requirements?
What is our design flow, EDA tools and methodology involved?
What is the estimated Chip cost?
Above all, the bottom line of any business model is money. What is our Profit model? What is our estimated ROI?
VLSI Design Flow
Step 1: Prepare a Requirement Specification
Step 2: Create a Micro-Architecture Document.
Step 3: RTL(Register Transfer Level) Design & Development of IP's(Intellectual Property)
Step 4: Functional verification all the IP's/Check whether the RTL is free from Linting Errors/Analyze whether the RTL is Synthesis friendly.
Step 4a: Perform Cycle-based verification(Functional) to verify the protocol behavior of the RTL
Step 4b: Perform Property Checking , to verify the RTL implementation and the specification understanding is matching.
Step 4c: Perform Clock Domain Crossing check, to verify that proper synchronization of control/data is there to ensure reliable cross domain data transfers.
The Chip Design Flow
The first step in chip design is the specification of the desired functionality and the technology that shall be used. In logic design, this functionality is made precise using some hardware description language. This hardware description is converted into a netlist that specifies which circuits have to be used and how they have to be connected to achieve the required functionality. The physical design step takes this netlist as input and outputs the physical location of each circuit and each wire on the chip. It will also change the netlist (in a logically equivalent way) in order to meet timing constraints. Before fabricating the chip (or fixing a hierarchical unit for later use on the next higher level), physical verification verifies that the physical layout meets all constraints and implements the desired functionality, and timing analysis checks that all signals arrive in time. Further testing will be done with the hardware once a chip is manufactured. From a mathematical point of view, physical design is the most interesting part of chip design as it requires the solution of several different challenging mathematical problems.
The structure of a Boolean circuit has a big impact on the performance and power consumption of a chip. On the one hand the depth, i.e. the maximum number of logic circuits on a combinatorial path should be small to meet the cycle time. On the other hand, the total number of circuits to realize a function should not be too big. Almost all Boolean functions have a minimum representation size which is exponential in the number of input variables. Hence, functions that are realized in hardware are quite special. Some very special functions, such as adders, certain symmetric functions, or paths consisting alternately of AND- and OR-circuits, can be implemented optimally or near-optimally by divide-and-conquer or dynamic programming algorithms. But general logic synthesis is done by (mostly local) heuristics today
Frequent Questions Asked
What do engineers have to decide when designing chip?
Engineering students who want something more challenging and creative than a routine software job can choose this field. A chip design engineer's job ranges right from the architecture, logic design, circuit design and physical design of the chip to the testing and verification of the final product
How do you make an integrated circuit?
In an integrated circuit, electronic components such as resistors, capacitors, diodes, and transistors are formed directly onto the surface of a silicon crystal. The process of manufacturing an integrated circuit will make more sense if one first understands some of the basics of how these components are formed.
How is IC chip made?
Hundreds of integrated circuits are made at the same time on a single, thin slice of silicon and are then cut apart into individual IC chips. The manufacturing process takes place in a tightly controlled environment known as a clean room where the air is filtered to remove foreign particles.