KITS(S)_2015 8
ENTITY testis
port a: in bit;
end ENTITY test;
DRC
LVS
ERC
Circuit Design
Functional Design
and Logic Design
Physical Design
Physical Verification
and Signoff
Fabrication
System Specification
Architectural Design
Chip
Packaging and Testing
Chip Planning
Placement
Signal Routing
Partitioning
Timing Closure
Clock Tree Synthesis
VLSI Flow
9.
Power IR Drop
Analysis
HierarchicalClock
Tree Synthesis
Full Chip Power
Planning
Block-Level Optimization
Timing
Closure
150ps
skew
120ps skew
50ps
skew
50ps
skew
100ps
skew
130ps
skew
Place
Detailed Trial Route
RC Extraction
Delay Calc / STA
IPO
Full Chip
Physical
Prototype
Partition
“Tape Out Every Day”
Cool Pictures of the Pieces…
M. Courtoy, Silicon Perspective
10.
Physical Prototype Partitioning
Block1
Block 2
Block 3
Block-Level Timing Budgets
Block-Level Pin Assignments
M. Courtoy, Silicon Perspective
Cool Pictures of the Pieces…
11.
Verilog/
VHDL
Library
Std., Cell.
Library
Tech file
Forlayout
values
Look up
Table for
timing
Tech file
For RC
Parasite
extraction
Design Analysis
Design Specification
Synthesis
Design Implementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Digital Design Flow
12.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Design Analysis
This is a very crucial step in digital
design where the design functionality
is stated.
Like if we are making a processor,
what type of functionality is expected??
Digital Design Flow
13.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Design Specification
This step involved stating in definite
terms the performance of the chip.
Like if we are making a processor,
data size, processor speed, special
functions, power etc. is clearly stated
at this point. Also somewhat it is decided,
the way to implement the design.
So, it deals with architectural part of the
design at highest level possible.
Based on these foundation , the whole
design is built
Digital Design Flow
14.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
HDL
Hardware Description Language is used
to run the simulations.
It is very expensive to build the entire
chip and then verify the performance of
the architecture. Imagine if after designing
a chip for a whole year, the chip fabricated,
does not come even closer to the stated
specifications.
Digital Design Flow
15.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
HDL (contd.)
Hardware description languages provides
a way to implement a design without going
into much architecture, simulate and verify
the design output and functionality.
For eg. rather than building a mux design
in hardware, we can write verilog code
and verify the output at higher level
of abstraction.
Examples of HDL: VHDL, Verilog HDL
Digital Design Flow
16.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
HDL (Contd.)
At this time we can see the design
in the form of Source Codes.
It seems more of the software
visualization of the circuit.
The simulated code is taken to
Synthesis to generate the Logic
Circuit.
Digital Design Flow
17.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Synthesis
Imagine the use of K-Maps and Truth
Tables to make and implement a digital
design.
If you notice, most of the digital designs
are build up of some basic elements or
components like gates, registers, counters,
adders, subtractors, comparators, RAM,
ROM etc.
It forms the fundamentals of Logic
Synthesis using EDA tools.
Digital Design Flow
18.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Synthesis (Contd.)
Standard Cell Library is the collection
of such building blocks which comprises
most of the digital designs.
These cell libraries are fabrication
technology specific.
Digital Design Flow
19.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Synthesis ( Contd.)
After the RTL simulation, the HDL,
code is taken as input by Synthesis
Tool and converted to Gate level.
At this stage that the digital design
becomes dependent on the
fabrication process.
At the end of this stage, we have
the logic circuit I.e. in terms of
gates and memories.
Digital Design Flow
20.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Synthesis ( Contd.)
What synthesis does is , when it
encounters a specific construct
in HDL it replaces it with the
corresponding Standard Cell
Component from the library to
build the entire design.
Like if we use a for loop , it gets
converted to counter and a
combinational circuit.
Digital Design Flow
21.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Synthesis ( Contd.)
The output of synthesis is a gate
level netlist.
Netlist is an ASCII file which
enlists and indicates the devices
and the interconnections
between
them.
Digital Design Flow
22.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Simulation
After the netlist is generated as part
of synthesis, this netlist is simulated
to verify the functionality of this
gate level implementation of design.
Till this level we just dealt with
functionality part. Now each step
onward deals with performance
part too.
Digital Design Flow
23.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Timing Analysis
RTL and Gate Level simulation
doesn’t take into account the physical
time delay in signal propagation from
one device to another and through
the device.
This time delay is dependent on the
fabrication process adopted.
Digital Design Flow
24.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Timing Analysis (Contd.)
Each component in standard cell
library is associated with some
specific delay.
Delay Lookup Tables list the
delays associated with the
components.
Delays are in the form of
rise time, fall time and turn off
time delays.
Digital Design Flow
25.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Timing Analysis (Contd.)
Most of the digital designs employ
concept of timing by using clocks.
This makes the circuits synchronous.
Digital Design Flow
26.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Timing Analysis (Contd.)
In timing analysis, using Delay
Lookup Tables, all the inputs
and outputs of components are
verified with timing introduced.
Digital Design Flow
27.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Place & Route
This is the actual stage where
the design implemented at
semiconductor layout level.
This the stage which really
requires more knowledge of
semiconductor physics than
digital design.
Digital Design Flow
28.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Place & Route (Contd.)
Semiconductor layout has to follow
certain design rules to lay devices
at semiconductor level.
These design rules are fabrication
process dependent.
The layout uses layers as p/n diffusion,
nwell, pwell, metals, via, iso etc.
Rules involving min. spacing, and
electrical relation between two layers
are known as DESIGN RULES.
Digital Design Flow
29.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Place & Route (Contd.)
Placement and Routing involves
laying of the devices, placing them
and making interconnection between
them, following the Design Rules.
The result is the design implemented
in the form of semiconductor layers.
Digital Design Flow
30.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Extraction
Once the layout is made, there always
is parasitic capacitances and resistances
associated with the design.
This is because of the compact layouts
to make the chips smaller. More you make
compact layout more will it introduce
these parasitic components. These
interferes in the functioning and
performance of the circuit in terms of
timing, speed and power consumption.
Digital Design Flow
31.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Extraction (Contd.)
Due to these factors it becomes very
much important to extract these devices
from layout and check the design for
performance and functionality.
Extraction would extract from the layout,
the devices formed because of junctions
of different semiconductor and metal
layers and the interconnections.
Digital Design Flow
32.
Design Analysis
Design Specification
Synthesis
DesignImplementation using HDL
Simulation
Timing Analysis
Place & Route
Extraction
Verification
Verification
Verification would either be the
tape out stage of the chip or the stage
where design is again taken back
through the same flow for
optimization or modification.
It verifies the extracted view of the
chip for performance and functionality.
Digital Design Flow
35
• ~ 70%of project development cycle: design verification
• Every approach to reduce this time has a considerable influence on economic success of a product.
• Not unusual for ~complex chip to go through multiple tape-outs before release.
Verification Costs
36.
36
• Verification isa bottleneck in the design process:
• High cost of design debug
• designers (sometimes verification engineers = 2 * design engineers)
• time-to-market
• High cost of faulty designs (loss of life, product recall)
Importance of Verification
37.
37
Problems found on1st spin ICs/ASICs
43%
20%
17%14%
12%
11%
11%
10%
10% 7% 4% 3% Functional Logic Error
Analog Tuning Issue
Signal Integrity Issue
Clock Scheme ErrorReliability Issue
Uses Too
Much Power
Mixed Signal Problem
Has Path Too Slow
Has Path Too Fast
IR Drop Issues
Firmware Error
Other Problem
Source: DeepChip, Aart de Geus, Chairman & CEO of Synopsys used it during Wed, 10 Sep 2003
Boston SNUG keynote address
Overall 61% of New ICs/ASICs Require At Least One Re-Spin
%43 due to functional error
38.
38
Flow of Simulation-BasedVerification
design
testbench design
simulation
debug
regression
revision control
bug tracking
coverage metrics
stimulus
generation
test plan linting
• Dashed line: Components specific to sim-
based methodology (are replaced by
components in formal methodology)
39.
2/10/03 ECE 426- Lecture 5 39
Functional Verification Approaches
• Black box
• Verify using module I/O ports only
• No knowledge of implementation
• No access to internals
• White box
• Verify using module I/O ports and internals
• Full knowledge of implementation
• Full access to internals during simulation
• Gray box
• Verify using module I/O ports only
• Full knowledge of implementation
• No access to internals during simulation
S.no Timings Topic
1.9.30 AM – 10.00 AM Inaugural Speech
2. 10.00 AM – 10.30 AM VLSI Intro, VLSI Flow etc..
3. 10.30 AM – 10.45 AM Networking Break
4. 10.45 AM – 11.00 AM Moore’s Law
5. 11.00 AM – 11.30 AM Chip Designing – Video Talk
6. 11.30 AM – 12.45 PM Importance of HDL
7. 12.45 PM – 1.30 PM Lunch Break
8. 1.30 PM – 2.30 PM Internet of Things
9. 2.30 PM – 3.00 PM Bio - Neuro VLSI and 3D chips
10. 3.00 PM – 3.15 PM Networking Break
11. 3.15 PM – 3.45 PM How to Write a Research paper?
12. 3.45 PM – 4.00 PM Higher Studies & Job Opportunities
13. 4.00 PM – 4.30 PM Closing Speech
KITS(S)_2015 44
Agenda
10.45 AM – 11.00 AM Moore’s Law
45.
KITS(S)_2015 45
Moore’s Law
Theperformance of an IC, including the number components on it, doubles every 18-24
months with the same chip price ... - Gordon Moore - 1960
S.no Timings Topic
1.9.30 AM – 10.00 AM Inaugural Speech
2. 10.00 AM – 10.30 AM VLSI Intro, VLSI Flow etc..
3. 10.30 AM – 10.45 AM Networking Break
4. 10.45 AM – 11.00 AM Moore’s Law
5. 11.00 AM – 11.30 AM Chip Designing – Video Talk
6. 11.30 AM – 12.45 PM Importance of HDL
7. 12.45 PM – 1.30 PM Lunch Break
8. 1.30 PM – 2.30 PM Internet of Things
9. 2.30 PM – 3.00 PM Bio - Neuro VLSI and 3D chips
10. 3.00 PM – 3.15 PM Networking Break
11. 3.15 PM – 3.45 PM How to Write a Research paper?
12. 3.45 PM – 4.00 PM Higher Studies & Job Opportunities
13. 4.00 PM – 4.30 PM Closing Speech
KITS(S)_2015 50
Agenda
11.30 AM – 12.45 PM Importance of HDL
51.
• Initially proprietarylanguage of Gateway Design Automation Inc.around 1984
• In 1989 Cadence acquired Gateway Design Automation
• In 1990 Cadence organized Open Verilog International(OVI)
• In 1995 Verilog became a IEEE standard Ieee 1364-1995
KITS(S)_2015 51
History of Verilog
52.
• Easier tounderstand than schematics
• Enables design at higher levels of abstraction
• Works on all available CAE(Computer aided Engineering ) Tools
• Provides Technology Independence
• Verilog can be coded for synthesis or simulation.
• Some constructs used for simulation can not be synthesized
• For Simulation CAE tools uses timing information defined in a Verilog model.
KITS(S)_2015 52
Importance of Verilog
• Carver Meadintroduce the term Neuromorphic Engineering to describe a new field of
engineering whose design principles and architecture are biologically Inspired.
• Neuro“to do with neurons i.e. neutrally inspired”
• Morphic “structure or form”
KITS(S)_2015 94
Neuromorphic Engineering
95.
• Build machinesthat have similar perception capabilities as human perception
• Adaptable and self organizing
• Robust to changing environments
Realisation of future “THINKING”machines
(intelligent and interactive systems)
KITS(S)_2015 95
Principles of Neuromorphic Technology
S.no Timings Topic
1.9.30 AM – 10.00 AM Inaugural Speech
2. 10.00 AM – 10.30 AM VLSI Intro, VLSI Flow etc..
3. 10.30 AM – 10.45 AM Networking Break
4. 10.45 AM – 11.00 AM Moore’s Law
5. 11.00 AM – 11.30 AM Chip Designing – Video Talk
6. 11.30 AM – 12.45 PM Importance of HDL
7. 12.45 PM – 1.30 PM Lunch Break
8. 1.30 PM – 2.30 PM Internet of Things
9. 2.30 PM – 3.00 PM Bio - Neuro VLSI and 3D chips
10. 3.00 PM – 3.15 PM Networking Break
11. 3.15 PM – 3.45 PM How to Write a Research paper?
12. 3.45 PM – 4.00 PM Higher Studies & Job Opportunities
13. 4.00 PM – 4.30 PM Closing Speech
KITS(S)_2015 100
Agenda
2.30 PM – 3.00 PM 3D chips
101.
•There is asaying in real estate; when land get expensive, multi-storied buildings are
the alternative solution.
KITS(S)_2015 101
3D Chips
102.
• The unprecedentedgrowth of the computer and the information technology industry
is demanding Very Large Scale Integrated (VLSI) circuits with increasing functionality
and performance at minimum cost and power dissipation.
• Continuous scaling of VLSI circuits is reducing gate delays but rapidly increasing
interconnects delays.
• Limits of Moore’s Law?
KITS(S)_2015 102
Motivation for 3D Chips
Many options availablefor realization of 3D circuits
Choice of Fabrication depends on requirements of Circuit System
• Wafer bonding
• Epitaxial growth
KITS(S)_2015 104
3D Fabrication Technologies
Die to Wafer
Wafer to Wafer
• 3D VLSIcan influence market only with high quality products improved quality/low cost will
sell
• Little immediate impact expected more research and small scale development needed
• expensive change of fabrication process required
• long time-to-market
KITS(S)_2015 107
Market
108.
• 3D VLSIrequires major paradigm shift in industry
• Initial participants -large capital risk to modify fabrication process
• Success of one company will require shift in industry as a whole (competition)
KITS(S)_2015 108
Impact
• Effective interdependencecollaborations among the key areas of biology, electrical & electronics
engineering, physiology and computer science are very fundamental to develop this emerging
area.
KITS(S)_2015 110
3D VLSI Key Areas
111.
• As thesystems mature, human parts replacements would become a major application area. The
fundamental principle is by observing how biological systems perform these functions robust
artificial systems are designed.
KITS(S)_2015 111
Future
112.
S.no Timings Topic
1.9.30 AM – 10.00 AM Inaugural Speech
2. 10.00 AM – 10.30 AM VLSI Intro, VLSI Flow etc..
3. 10.30 AM – 10.45 AM Networking Break
4. 10.45 AM – 11.00 AM Moore’s Law
5. 11.00 AM – 11.30 AM Chip Designing – Video Talk
6. 11.30 AM – 12.45 PM Importance of HDL
7. 12.45 PM – 1.30 PM Lunch Break
8. 1.30 PM – 2.30 PM Internet of Things
9. 2.30 PM – 3.00 PM Bio - Neuro VLSI and 3D chips
10. 3.00 PM – 3.15 PM Networking Break
11. 3.15 PM – 3.45 PM How to Write a Research paper?
12. 3.45 PM – 4.00 PM Higher Studies & Job Opportunities
13. 4.00 PM – 4.30 PM Closing Speech
KITS(S)_2015 112
Agenda
3.00 PM – 3.15 PM Networking Break
113.
S.no Timings Topic
1.9.30 AM – 10.00 AM Inaugural Speech
2. 10.00 AM – 10.30 AM VLSI Intro, VLSI Flow etc..
3. 10.30 AM – 10.45 AM Networking Break
4. 10.45 AM – 11.00 AM Moore’s Law
5. 11.00 AM – 11.30 AM Chip Designing – Video Talk
6. 11.30 AM – 12.45 PM Importance of HDL
7. 12.45 PM – 1.30 PM Lunch Break
8. 1.30 PM – 2.30 PM Internet of Things
9. 2.30 PM – 3.00 PM Bio - Neuro VLSI and 3D chips
10. 3.00 PM – 3.15 PM Networking Break
11. 3.15 PM – 3.45 PM How to Write a Research paper?
12. 3.45 PM – 4.00 PM Higher Studies & Job Opportunities
13. 4.00 PM – 4.30 PM Closing Speech
KITS(S)_2015 113
Agenda
3.15 PM – 3.45 PM How to Write a Research Paper?
KITS(S)_2015 117
• Ifyou ever tinkered with a broken radio set, you have already started.
• Academically, the right time to acquaint yourself with various specializations of Electronics is
when you are in second or third year of engineering.
When is the right time to think about VLSI ?
118.
KITS(S)_2015 118
What Sortof Jobs does an Electronic Engineer do ?
ENTITY test is
port a: in bit;
end ENTITY test;
DRC
LVS
ERC
Circuit Design
Functional Design
and Logic Design
Physical Design
Physical Verification
and Signoff
Fabrication
System Specification
Architectural Design
Chip
Packaging and Testing
Chip Planning
Placement
Signal Routing
Partitioning
Timing Closure
Clock Tree Synthesis
119.
S.no Timings Topic
1.9.30 AM – 10.00 AM Inaugural Speech
2. 10.00 AM – 10.30 AM VLSI Intro, VLSI Flow etc..
3. 10.30 AM – 10.45 AM Networking Break
4. 10.45 AM – 11.00 AM Moore’s Law
5. 11.00 AM – 11.30 AM Chip Designing – Video Talk
6. 11.30 AM – 12.45 PM Importance of HDL
7. 12.45 PM – 1.30 PM Lunch Break
8. 1.30 PM – 2.30 PM Internet of Things
9. 2.30 PM – 3.00 PM Bio - Neuro VLSI and 3D chips
10. 3.00 PM – 3.15 PM Networking Break
11. 3.15 PM – 3.45 PM How to Write a Research paper?
12. 3.45 PM – 4.00 PM Higher Studies & Job Opportunities
13. 4.00 PM – 4.30 PM Closing Speech
KITS(S)_2015 119
Agenda
4.00 PM – 4.30 PM Closing Speech