sistec microelectronics vlsi design
DESCRIPTION
VLSI DesignTRANSCRIPT
A New Trends in Integration Technologies
Dr. Ravi Shankar Mishra
Prof. & HOD
•The growth of electronics industry has increased
rapidly mainly due to advances in integration
technologies, large-scale systems design - due to the
advent of VLSI.
•The number of applications of integrated circuits are
in high-performance computing, telecommunications,
and consumer electronics.
VLSI TECHNOLOGY AND DESIGN DRIVERS
• Less Area, More Compactness At All System Levels
• Less Power Consumption
•Fewer Chips/components Per Board And System
• Higher Reliability, Due To Improved On-chip
Interconnects
• Higher Speed Due To Reduced Interconnect Length
Manufacturing Cost Reductions
CLASSIFICATION OF ICS
Based onApplication
Based on
Fabrication Techniques Based on Technology
Based on Device Count
Linear
ICDigital IC
Monolithic IC
Hybrid IC
BJT MOSFET
SSI
MSI
LSI
VLSI
ULSI
19471906
Audion (Triode), 1906
Lee De Forest
First point contact transistor (germanium), 1947
John Bardeen and Walter Brattain
Bell Laboratories
IC Evolution
First integrated circuit (germanium), 1958Jack S. Kilby, Texas Instruments
Contained five components, three types:transistors resistors and capacitors
Intel Pentium II, 1997Clock: 233MHz
Number of transistors: 7.5 MGate Length: 0.35
19581958 19971997
Pentium® III28M transistors / 733MHz-1Gz / 13-26W
L=0.25µm shrunk to L=0.18µm
Pentium® 4 “Northwood”55M transistors / 2-2.5GHz
L=0.13µm
IC Evolution
SSI – Small Scale Integration (early 1970s)contained 1 – 10 logic gates
MSI – Medium Scale Integration logic functions, counters
LSI – Large Scale Integrationfirst microprocessors on the chip
VLSI – Very Large Scale Integrationnow offers 64-bit microprocessors,complete with cache memory,floating-point arithmetic unit(s), etc.
Bipolar technology
TTL (transistor-transistor logic)
ECL (emitter-coupled logic)
MOS (Metal-oxide-silicon)
NMOS (n-channel MOS) technology developed in 1970s required fewer masking steps, was denser, and consumed less power than equivalent bipolar ICs an MOS IC was cheaper than a bipolar IC and led to investment and growth of the MOS IC market.
Aluminum gates for replaced by polysilicon by early 1980
CMOS (Complementary MOS): n-channel and p-channel
MOS transistors =>
lower power consumption, simplified fabrication process
Bi-CMOS - hybrid Bipolar, CMOS (for high speed)
GaAs - Gallium Arsenide (for high speed)
Si-Ge - Silicon Germanium (for RF)
“Moore’s Law”
The number of transistors that can be integrated on a single IC grows exponentially with time.
“Integration complexity doubles every three years”
Gordon MooreFairchild Corporation - 1965
Design Abstraction Level
A complex digital system can be subdivided in a hierarchical manner using abstraction.
System Design
logic Design
Circuit Design
Layout Design
Blocks, sub-blocks Logic gates FETs Geometric
structures
DESIGN PROCESS
• Behavioral design
It deal with function of the system & register input and output.
• Data path design
In this flow of data through buses between registers and logic unit are controlled.
• Logic design
Data path units are replaced with primitive gates & flip flop.
• Physical design
It replaces the gates and flip flop using transistors.
DESIGN AUTOMATION
The function or operations for transforming design or one stage into other stage and verification of the out put done by the software known as design automation the tool use for this.
• Simulation tools or simulators.
• Synthesizers.
Simulation
It is the process of verifying the conduction of model for the given
circuit without implementing practically.For this purpose Modelsim simulator used output of simulator is wave form or timing diagram.
Synthesis
The process of transforming design description from one form two another form is called synthesis.
DESIGN METHODOLOGIES
Fully Custom Semi Custom
Standard Cells Gate Arrays Programmable Logic
FPGA PLD
•Customers decide the design methodology
• Full Custom Each And Every Component design as per designer interest.
• Semi Custom Designer can design part of the project and part of thing can be
taken from others.
• Standards cells Predefined logic cells are called standards cells. Pre design
modules e.g. AND gate,OR gate,Multiplexers, Flip Flop.
• Gate Array In this standard logic elements or present for the designer to the interconnect to achieve the desire function.
• Field Programmable Devices
It is prefabricated, the logic is implemented by electrically
programming the interconnects.
Application-Specific Integrated Circuit (ASIC)
A kind of semi custom integrated circuit, often referred to as
"gate-array" or "standard-cell" products, developed & designed
to satisfy a specific application requirement as opposed to a
general purpose circuit, such as a microprocessor.
•ASICs are customized or tailored to perform specific functions to a
particular system or application
• ASICs are typically employed as bus interfaces, glue
logic,functional accelerators, and/or a System-On-Chip (SoC).
ASIC – Benefits
•Improve performance
• Reduce power consumption
• Reduce production costs
• Mix Analog and Digital Designs
• Design optimization through IC manufacturing process
• Development Tools support HDL and Schematic design approach
System-on-a-chip (SOC)
Idea: combine several large blocks
Pre design custom cores
(e.g.,microcontroller) - “intellectual property” (IP)
ASIC logic for special-purpose hardware
Programmable Logic (PLD, FPGA)
VLSI Design Tools
Front End Design tools:
With the help of these tools simulation & synthesis of circuit can be performed on PC.E.g. XILINX, Altera etc.
Back End Design Tools:
These tools are used to fabrication purpose.The layout of circuit is design and simulate with the help of these tools. E.g. TANNER,MICROWIND
.
Application of VLSI
Ultra Low power Image & Video Compression.
Encryption Chip/Smart Card
CMOS Image Sensor
Medical electronic systems.
Real time Tele communication and Data
Processing application
Process control industry etc……