1. Introduction to VLSI design.pdf

VLSI Design 20EC502 Lecture No. 1 T.Y. B. Tech Semester I E & TC Department Evolution IC technology VLSI 2  History of Integration Small Scale Integration (SSI) ~ 10 gates 60’s Gates,...

VLSI Design 20EC502 Lecture No. 1 T.Y. B. Tech Semester I E & TC Department Evolution IC technology VLSI 2  History of Integration Small Scale Integration (SSI) ~ 10 gates 60’s Gates, Op-amps Medium Scale Integration (MSI) ~ 100-1000 gates 70’s Filters Large Scale Integration (LSI) ~ 1000-10,000 gates 80’s Microprocesso rs, A-D Very Large Scale Integration (VLSI) ~ 10,000-100,000 gates 90’s Memory, DSP Ultra Large Scale Integration (ULSI) ~ 10,00,000-1,00,00,000 gates (~ 1million -10 million gates) VLSI 3 Moore’s Law VLSI 4 Current Trends VLSI 5  VLSI Design Flow VLSI 6  VLSI Design Flow VLSI 7 Simplistic View of VLSI Design Flow VLSI 8  Design Flow It is a standardized design procedure which involves multiple stages and helps to achieve actual implementation of idea. To deal at multiple stages CAD tool requires. It transforms its HDL input into a HDL output that contains more hardware information Behavioral level to register transfer level Register transfer level to gate level Gate level to transistor level Designs are created typically using HDL’s which get transformed from one level of abstraction to the other as the design flow progresses. VLSI 9  Steps in the design Flow Behavioral Design Specify the functionality of the chip Data Path Design Generate a netlist of register transfer level components Logic Design Generate a netlist of gates/flip-flops or standard cells Physical Design Generate the final layout Manufacturing Fabricate the chip VLSI 10  Other steps in the design Flow Simulation for verification At various levels : logic level, switch level , circuit level Formal Verification Used to verify the designs through formal techniques Testability analysis and Test pattern generation Required for testing the manufactured devices VLSI 11  Design Representation A design can be represented at various levels from 3 different angles: Behavioral Structural Physical Can be represented by Y-diagram VLSI 12  Design Representation : Y-diagram VLSI 13  Design Representation : Y-diagram VLSI 14  Behavioral Representation Specifies how a particular design should respond to a given set of inputs May be specified by: Boolean equations Tables of input and output values Algorithms written in standard HLL like C Algorithms written in special HDL like Verilog or VHDL VLSI 15  Specifies how components are interconnected Structural Representation In general, the description is a list of modules and their interconnects Called Netlist Can be specified at various level At the structural level, the levels of abstraction are Module(functional) /level Gate level Switch level Circuit level In each successive level more details areVLSI revealed about the implementation 16  Physical Representation Lowest level of physical specification Photo-mask information required by the various processing steps in the fabrication process VLSI 17  EDA tools used in VLSI Electronic Design Automation, or EDA, is a market segment consisting of software, hardware, and services with the collective goal of assisting in the definition, planning, design, implementation, verification, and subsequent manufacturing of semiconductor devices, or chips. While EDA solutions are not directly involved in the manufacture of chips, they play a critical role in three ways. First, EDA tools are used to design and validate the semiconductor manufacturing process to ensure it delivers the required performance and density. This segment of EDA is called technology computer-aided design, or TCAD. VLSI 18  EDA tools used in VLSI Second, EDA tools are used to verify that a design will meet all the requirements of the manufacturing process. Deficiencies in this area can cause the resultant chip to either not function or function at reduced capacity. There are also reliability risks. This area of focus is known as design for manufacturability, or DFM. The third area is relatively new. After the chip is manufactured, there is a growing requirement to monitor the performance of the device from post-manufacturing test to deployment in the field. The goal of this monitoring is to ensure the device continues to perform as expected throughout its lifetime and to ensure the device is not tampered with. This third application is referred to as silicon lifecycle management, or SLM VLSI 19  How Does EDA Work? Electronic Design Automation is primarily a software business. Very sophisticated and complex software programs function primarily in one of three ways to assist with the design and manufacture of chips: Simulation tools take a description of a proposed circuit and predict its behavior before is it implemented. Design tools take a description of a proposed circuit function and assemble the collection of circuit elements that implement that function. This is both a logical process (assemble and connect the circuit elements) and a physical process (create the interconnected geometric shapes that will implement the circuit during manufacturing). These tools are delivered as a combination of fully automated and interactively guided capabilities. VLSI 20  How Does EDA Work? Verification tools examine either the logical or physical representation of the chip to determine if the resultant design is connected correctly and will deliver the required performance. While most EDA products are delivered as software, there are some cases where physical hardware is also used to deliver capabilities VLSI 21  History of EDA tools EDA began as a captive capability. Before EDA was a market segment, large, vertically integrated OEMs operated captive chip design and manufacturing capabilities. These organizations employed large teams of software engineers to develop the required tools to automate the design, implementation, and verification of the chips that were manufactured. All chip production in this case was used by the OEMs to include in their own products. Bell Laboratories, Texas Instruments, Intel, RCA, General Electric, Sony, and Sharp are examples of these companies. The birth of commercial EDA tools essentially happened in three phases. VLSI 22  History of EDA tools The first phase began in the 1960s and saw commercial availability of computer-assisted interactive graphics design systems. These systems targeted multiple markets, including cartography, mechanical, and architectural design. These systems also found use for interactive design of integrated circuit layouts. The three primary companies leading this phase were Applicon, Calma, and Computervision. It is interesting to note that in these early days Calma developed a format to represent IC layouts called GDS, named after its product, Graphic Design System. The GDS II version of this format continued to be used as the de-facto format to communicate IC layout information for decades. This phase of the industry was known as CAD/CAM (computer-aided design/computer-aided VLSI 23  History of EDA tools Second phase of EDA began in the early 1980s. Something rather significant happened during this time – the commercial application-specific integrated circuit, or ASIC, industry was also born. With the emergence of the ASIC industry, the custom chips that were previously reserved for the very large system OEMs were now within reach of many more design teams. This began the semiconductor revolution that continues today. Early ASIC companies include LSI Logic and VLSI Technology. With this new market, the need for tools to automate the simulation, design, and verification of chips became far more widespread. VLSI 24  History of EDA tools This development spawned many new companies to serve the need. A lot of the internal, captive teams at the large OEMs found new, exciting, and lucrative work in this new market and so the commercial EDA industry began to grow. During this phase, the primary focus was on software and some special-purpose hardware to capture the description of a design and simulate it. The three primary companies leading this phase were Daisy Systems, Mentor Graphics, and Valid Logic. This phase was known as CAE (computer-aided engineering). VLSI 25  History of EDA tools In the latter part of the 1980s, the EDA industry began to mature as its third phase began. Point-tool companies were replaced with broad-line suppliers of multiple software and hardware products aimed at automating a larger portion of the IC design process. The three primary companies leading this phase were Synopsys, Cadence, and Mentor (now Siemens EDA). This phase saw the birth of the term EDA (electronic design automation). Today, many still identify with this phase of the industry. The three leading companies remain the same. With the dramatic expansion of semiconductor technology, there is a movement toward a need for a larger platform of tools and technologies which may signal the next phase of the industry’s development. VLSI 26  Types of EDA tools Simulation: Simulation tools take a description of a proposed circuit and predict its behavior before is it implemented. This description is typically presented in a standard hardware description language such as Verilog or VHDL. Simulation tools model the behavior of circuit elements at various degrees of detail and perform various operations to predict the resultant behavior of the circuit. VLSI 27  Types of EDA tools Verification: These tools examine either logical or physical representation of the chip to determine if the resultant design is connected correctly & will deliver the required performance Physical verification examines the interconnected geometries to ensure their placement obeys the manufacturing requirements of the fab. These requirements have become very complex and can include more than 10,000 rules. Verification can also take the form of comparing the implemented circuit to the original description to ensure it faithfully reflects the required function VLSI 28  Types of EDA tools Verification: Layout vs. schematic, or LVS, is an example of this process. Functional verification of a chip can also use simulation technology to compare actual behavior to expected behavior. These approaches are limited by the completeness of the input stimulus provided. Another approach is to verify the behavior of the circuit algorithmically, without the need for input stimulus. This approach is called equivalence checking and is a part of a discipline known as formal verification. VLSI 29  Popular EDA tools 01. Cadence Virtuoso The cadence virtuoso design platform allows integrated circuit designers to design layout, schematic, create test-bench, and also DRC (design rule check) verification, LVS (layout versus schematic) verification, parasitic capacitance verification, with community support and libraries. Cadence is a very popular tool for VLSI chip design. VLSI 30  Popular EDA tools 2. Synopsys Synopsys is an EDA company that offers silicon design and verification. This tool includes logic synthesis, route and place, behavioural synthesis, static timing analysis, HDL simulators, format verification, and transistor-level circuit simulation. 3. Mentor Graphics The mentor system IC design tool features ahead, high performance, simple-to-use schematic and layout editor, alliance with best-in-class circuit simulators, and combination with calibre, the industry-leading solution for parasitic extraction, design rule checking, and physical verification VLSI 31  Popular EDA tools 04. Xilinx The Xilinx is a tool created by Xilinx for analysis and synthesis of the HDL designs, and it will also help developers to synthesize their design, examine register transfer level (RTL) diagrams, perform timing analysis, etc. 05. Tanner Tanner EDA(electronic design automation) offers a complete line of software solutions for the layout, design, and verification of analog and mixed-signal ICs (integrated circuits). Tanner’s solution includes tools for circuit simulation, schematic entry, waveform probing, full-custom layout editing, routing and placement, netlist extraction, and design rule check (DRC) verification. VLSI 32  Popular EDA tools 06. Electric The electric VLSI design system is an EDA tool was discovered in 1980s. This tool is used to draw schematics and layout of integrated circuit. Electric tool can also handle hardware description languages such as verilog and VHDL. This tool has many synthesis and analysis tools such as design rule check, routing, layout versus schematic, etc. 07. Silvaco Silvaco provides a full IC-CAD design flow which consists of circuit simulation, design capture, physical verification, layout design, parasitic extraction and reduction, and post-layout which consists of statistical variation, IR-drop/EM. VLSI 33  Popular EDA tools 08. Glade Glade is an IC layout and schematic editor capable of learning and writing simple EDA formats. With made-in DRC, extraction, and LVS you can produce and verify schematics and layout in a single customizable tool. Glade can load and present large design databases with its fast, lightweight object-oriented database. Delivered now for over 15 years, Glade held the first free layout editor accessible for windows. Glade is extendable employing python scripting, providing access to the database and GUI via SWIG wrapping of C++ functions. VLSI 34  Popular EDA tools 09. Alliance The alliance is a full set of free CAD tools and compact libraries for VLSI design. I It holds a VHDL compiler and simulator, logic synthesis tools, and automatic place and route tools. A full set of compact CMOS libraries is given. The alliance is the result of a twelve-year work spent at the SoC department of LIP5 laboratory of the Pierre & Marie Curie University. Alliance has done used for research projects so as the 875000 transistors super-scalar microprocessor. Alliance VLSI CAD system is free software, binaries, source code, and cell libraries are freely accessible under the General Public License. VLSI 35  Popular EDA tools Design Entry tools: Viewlogic (ViewDraw – a hierarhical schematic capture and block diagram tool) Mentor Graphics (Renoir) Cadence Design System OrCAD ALDEC(Active-HDL) Simucad(Silos-3) VLSI 36  Popular EDA tools Design Simulation tools: Model Technology (MOdelsim) Synopsys VCS (High Performance Verilog Simulation) VSS (High Performance VHDL Simulation) Cadence Verilog XL Simulator DRACULA- physical verification standard Quickturn Design Systems (Powersuite) VIVElogic (Fusion/Speedwave – a VHDL Simulator) VLSI 37  Popular EDA tools Logic Synthesis and Optimization tools: Synopsys FPGA Express FPGA Compiler Synplicity - Synplity Exemplar logic – Leonardo Spectrum VIVElogic – Intelliflow Cadence Design System ALDEC –(Active HDL) VLSI 38 Overview of SoC VLSI 39 VLSI 40 Technology Paradigm VLSI 41 Comparison of CoB, SIP and SoC VLSI 42  What is SoC? SoC SoC stands for System On Chip. It is a small integrated chip that contains all the required components and circuits of a particular system. What it consist of? The components of SoC includes: CPU (Central Processing Unit), GPU(Graphic Processing Units), ISP(Image Sensor Processor, DSP(Digital Signal Processor), NPU(Network Processing Unit, GPS(Global Position System), RAM(Random Access Memory), Baseband Communication Unit and so on. Where it is used? SoC is used in various devices such as smartphones, Internet of Things appliances, tablets, and embedded system applications. VLSI 43  SoC: Most Critical Part of Modern Smart Phone It effectively functions as a single unit and is responsible for handling almost every single task you ask your phone to perform. Be it something relatively mundane as making and receiving calls to something inherently more complex, like using the phone camera to click pictures and videos, then edit and render a final product using an editing app. What is ARM architecture: ARM is a British company that owns the license to the ARM architecture, instruction set and CPU core design that is used by all companies that make SoCs. No matter what smartphone brand you buy, and immaterial of the SoC it uses, it is a given that it is based on the ARM architecture. VLSI 44  What components does an SoC contain? Central Processing Unit(CPU): The single most important component of the modern smartphone, the CPU, is the actual brain behind your smartphone. A modern smartphone CPU typically has several cores, and its performance is measured in GigaHertz (GHz). When we talk about smartphone performance, we will often use terms like ‘Cortex-A77’ or ‘Cortex-A53’. These are the names of the actual CPU core that nestle within the SoC. VLSI 45  What components does an SoC contain? Graphics Processing Unit (GPU) While the CPU can handle several tasks, it is not specifically designed to handle graphics. Since most smartphones of today need to process highly demanding games (and video content), this task is handled by a dedicated GPU. You will hear a lot about GPUs in smartphone reviews VLSI 46  What components does an SoC contain? Image Processing Unit (ISP) Modern smartphones usually have a separate image processing unit. This essentially allows them to ‘convert’ data from an image sensor to a usable photo that you can then edit and share with friends and relatives. In the past, the CPU used to handle this task as well. But manufacturers soon realized it is always a better idea to offload these tasks to a separate Image Processing Unit. Names you shall come across when discussing ISPs include ‘Spectra’ from Qualcomm and Imagiq from MediaTek. VLSI 47  What components does an SoC contain? Integrated Modems Modern smartphones are communication devices, and a modem is the single most essential component that enables this basic feature. A modem is used to convert wireless signals into data that phone can understand. Today’s smartphone modems integrate 5G, 4G, 3G, and Wi-Fi capabilities in a single unit. While a majority of smartphone SoCs today feature an integrated modem, there are a few exceptions. VLSI 48  Other components in SoC Digital Signal Processor (DSP) — Handles more mathematically intensive functions than a CPU. Includes decompressing music files and analysing gyroscope sensor data. Neural Processing Unit (NPU) — Used in high-end smartphones to accelerate machine learning (AI) tasks. These include offline voice recognition and camera object segmentation. (Siri, Alexa, Bixby, etc) Video encoder/decoder — Handles the power-efficient conversion of video files and formats Sensors : The fifth part is for managing various sensors on your phone. Security: The sixth part is for managing security on your phone, as simple as your biometric scanning for locking and unlocking your phone. VLSI 49  Who Make Smart Phone SoC ? The major players in the smartphone SoC segment include the following companies. Apple Qualcomm MediaTek Samsung HiSilicon Unisoc VLSI 50  Apple SoC’s Since Apple does not need its SoCs to use on several devices, it typically announces just one smartphone SoC every year. Until 2010, Apple relied on Samsung-sourced SoCs for the iPhone and iPad models. Since then, however, the company moved to its own ARM-based SoCs. The first Apple-designed SoC was the Apple A4 which debuted in 2010. A decade on, the newest smartphone SoC from Apple is called the Apple A15 Bionic which is used on the iPhone 13 series. It is widely thought to be the most powerful SoC currently available for any smartphone. VLSI 51  Apple’s latest mobile processor – A15 Bionic is the Apple SoC’s choice powering the iPhone 13 /13 Pro models and the 6th-Gen iPad mini SoC arrives with a similar 5nm process technology and 6-Core CPU (2x high performance – codenamed Avalanche + 4x efficiency cores – codenamed Blizzard) as the A14 Bionic (iPhone 12/12 Pro series), however, performance and power efficiency has considerably increased, according to Apple. Manufactured by Taiwan Semiconductor Manufacturing Company (TSMC) VLSI 52  Apple A15 Bionic also contains 15 billion Apple SoC’s transistors, a new ISP and faster neural network (16-Core Neural Engine), which processes 15 trillion operations per second (compared to 11.8 trillion operations per second on the A14 Bionic). Various sources believed that TSMC used the more advanced second generation 5nm architecture called N5P for the A15 Bionic and the new ISP powers the respective advanced dual and triple cameras systems on the iPhone 13 series and iPhone 13 Pro series. VLSI 53  The new neural network provides faster machine Apple SoC’s learning applications including the new Live Text feature in iOS 15. There are two GPU configurations: a 4-core GPU and a 5-Core GPU. 4-Core GPU in the iPhone 13 delivers up to 15% increase in graphic performance over the A14 Bionic and up to 30% faster than the closest competition. 5-core GPU delivers up to 55% increase in graphics performance in the iPhone 13 Pro over its predecessor and up to 50% faster than the closest competition. VLSI 54 VLSI 55  Qualcomm SoCs An American company, Qualcomm, is the most widely known smartphone SoC company. Its smartphone SoCs are sold under the Snapdragon brand. Qualcomm designs and sells a wide variety of SoCs ranging from entry-level and mid-range to high-end SoCs and is perhaps the most widely known brand in this segment. Qualcomm Snapdragon 800 series The 800 series SoCs from Qualcomm has long held the title of being the most powerful chipsets available for Android smartphones. These chipsets are typically used on high-end Android smartphones. In 2022, the top-of-the-line flagship Snapdragon 8 gen 1. VLSI 56  Its predecessors include: Qualcomm SoCs Snapdragon 888/888+ from 2021, Snapdragon 865/865+ from 2020, Snapdragon 855/855+ from 2019 Qualcomm Snapdragon 700 series SoCs from Qualcomm's 700 series are positioned one rung below the more powerful 800 series chips and are typically used on upper mid-range smartphones. While not as powerful as 800 series , the 7 series have almost equivalent features and only make small compromises either on the processing speed or graphics departments. Examples of Snapdragon 765G, Snapdragon 732G, and the Snapdragon 720G VLSI 57  Qualcomm SoCs Qualcomm Snapdragon 600 series Among the most popular smartphone SoCs, you will find Snapdragon 600 series chipsets on popular budget smartphones that typically offer a lot of features for very little money. While these SoCs are not nearly as powerful as their 700 and 800 series brethren, most 600 series SoCs are quite capable of handling all tasks that an average smartphone user would throw at them. These SoCs feature adequately powerful GPUs that let users play the most graphically intensive games as well without breaking too much sweat. The Snapdragon 675G, Snapdragon 670, and Snapdragon 665 are some SoCs from this lineup. VLSI 58  Qualcomm Snapdragon 400 series Qualcomm SoCs Snapdragon 4 series SoCs are typically used on smartphones that go for very low prices. While these SoCs can handle most daily tasks, they are not designed for resource-intensive tasks like multitasking or playing games. It includes the Snapdragon 460, Snapdragon 450, and Snapdragon 439 SoCs. Qualcomm Snapdragon 200 series Smartphones that use these very basic SoCs are usually sold in emerging markets. Another key trait with the owners of these phones is that almost all of them have recently upgraded from basic feature phones. Examples: Snapdragon 215, Snapdragon 212,VLSISnapdragon 205 59 Qualcomm SoCs VLSI Snapdragon 820 Mobile SoC 60  MediaTek SoCs Known for its affordable SoCs that were typically used on cheaper smartphones, MediaTek is a Taiwanese company that designs smartphone SoCs. Of late, however, they have managed to pose a significant threat to Qualcomm’s domination in the segment thanks to its competitive entry-level and mid-range products. MediaTek Dimensity 5G 5G centric smartphone SoC series. Unlike the Qualcomm 800 series, which is targeted only at flagship products, MediaTek’s Dimensity lineup includes flagship-grade, mid-range, and budget SoCs. VLSI 61  MediaTek Helio G MediaTek SoCs Gaming-focused chipsets that typically cater to the entry-level and budget gaming audience. Examples like the entry-level Helio G25 to relatively powerful Helio G95. MediaTek Helio P The Helio P series is a popular line of budget SoCs from MediaTek. P series is near-identical to their cousins from the G series, G series has slightly better GPU. Helio P95, P90, and P70 in the top end, Helio P60 and P65 in the mid-range and Helio P20 series (P20, P22, P25) in the entry-level segment. MediaTek Helio A Always found on low-end Android smartphones - A series includes Helio A20, A22, and A25 VLSI 62  Samsung SoC’s Samsung is a South Korean conglomerate that has several business units. It also has a semiconductor unit that designs its own lineup of smartphone SoCs branded as Exynos. In late 2020, high-end SoC – the Exynos 1080, which was also its 5nm SoC. Samsung came up with the powerful Exynos 2100, which is currently top-tier flagship SoC. Entry Level and Mid Range Exynos SoCs As of 2021, Samsung’s mid-range SoC lineup includes the Exynos 9600 series that includes SoCs like the Exynos 9609, 9610, and 9611. These SoCs - the 9611 in particular- are widely used on the company’s budget handsets. Then there is the Exynos 7000 series which is positioned below the 9000 series and is typically used on entry-level phones VLSI 63  HiSilicon (Huawei) SoCs Chinese telecommunications giant Huawei is another brand that has its own lineup of smartphone SoCs. It is manufactured by a subsidiary company called HiSilicon, and its smartphone SoCs are marketed under the ‘Kirin’ brand. Kirin 900 and 9000 series The current flagship SoCs from HiSilicon belong to the Kirin 9000 series and include two SoCs - the Kirin 9000 and the 9000E. Their 2020 flagship SoCs included SoCs from the Kirin 990 lineup and included the Kirin 990, Kirin 990 5G, and the Kirin 990E 5G. VLSI 64  HiSilicon (Huawei) SoCs Kirin 800 series The Kirin 800 series is positioned just below the flagship 900 series SoCs and is designed to be used on Huawei’s affordable flagship and upper mid-range handsets. The newest product from this lineup is the Kitin 820E 5G and its sibling, the Kirin 8205G. Kirin 700 and Kirin 600 series Huawei extensively used SoCs from the Kirin 700 and 600 series on its budget handsets. These SoCs are designed to compete against Qualcomm’s 600 and 700 series SoCs. However, this lineup hasn’t seen much in terms of new developments since 2017-18 VLSI 65  Unisoc SoCs (Previously Spreadtrum) Unisoc is yet another smartphone SoC brand. While not as famous as the likes of Qualcomm, MediaTek, Samsung, or Huawei, Unisoc does have a comprehensive set of smartphone focused SoCs. They are mostly used by manufacturers who concentrate on manufacturing devices targeted at the lower end of the price spectrum. The company did recently announce a powerful 5G enabled SoC called the Unisoc Tiger T7520 SoC, which is based on a 6nm manufacturing process. The only other 5G ready SoC from the company is the older Unisoc T7510 SoC which is a budget 5G SoC launched in mid-2020. Unisoc does have a wide portfolio of 4G-ready SoCs that include the likes of the T710, T618, and T610 SoCs. VLSI 66 Architecture of System on Chip (SoC) VLSI 67  System on Chip Network Interface card: SoC has an internal interface or bus or network to connect all individual blocks. The Network interface card provides a connection of the network to the system. GPU: GPU stands for Graphical Processing Unit, used in SoC to visualize the interface. GPU is specially designed to speed up the operations related to image calculations. The basic blocks of the GPU are the Bus interface, Power Management Unit, Video Processing unit, Graphics Memory Controller, Display interface, etc. VLSI 68  System on Chip Peripheral devices: Externally connected devices/interfaces such as USB, HDMI, Wi-Fi, and Bluetooth are included in peripheral devices. This device is used in SoC to perform various operations. UART: Universal Asynchronous Receiver Transmitter is included in SoC which is used to transmit or receive serial data. Voltage regulators, Oscillators, clocks, and ADC/DAC are also part of SoC. VLSI 69 Application of VLSI IC With the advent of very large scale integration (VLSI) designs, the number of applications of integrated circuits (ICs) in high-performance computing, controls, telecommunications, image and video processing, and consumer electronics has been rising at a very fast pace. VLSI 70