Transcript lecture06 - Brown University

Design and Implementation of VLSI Systems
(EN1600)
lecture06
Prof. Sherief Reda
Division of Engineering, Brown University
Spring 2008
[sources: Weste/Addison Wesley – Rabaey/Pearson]
S. Reda EN160 SP’08
Computer-Aided Design (CAD) Tools
• Early days were easy. The first IC-based microprocessor 4004 from Intel
had only 2300 transistors (manufactured in 10 micron technology).
Almost manual design.
• Current chips has well about 1B transistors. To get the chip to market
fast, CAD tools are needed.
S. Reda EN160 SP’08
A simple tool chain
specifications
Hardware
Description
Languages
if
SEL == “00“ then Y
elseif SEL == “01“ then Y
elseif SEL == “10“ then Y
else
Y
end if;
A;
B;
C;
D;
schematic entry
2:1 MUX
2:1 MUX
D
synthesis
=
=
=
=
2:1 MUX
C
B
Y
A
SEL == 10
SEL == 01
SEL == 00
IC layout/
area
Layout and routing
simulation
Verification and timing/ power results
S. Reda EN160 SP’08
Cell library
Design Layout using Tanner L-Edit
S. Reda EN160 SP’08
How to implement the layout for an inverter?
S. Reda EN160 SP’08
1. First setup technology
Use AMI 0.5μ submicron technology
(λ=0.3μ)
S. Reda EN160 SP’08
Design rules are a bit different than book
active
metal
S. Reda EN160 SP’08
polysilicon
contacts
Adjust design in terms of lambda
S. Reda EN160 SP’08
N well creation
S. Reda EN160 SP’08
Active region
S. Reda EN160 SP’08
P-Select
S. Reda EN160 SP’08
N-select
S. Reda EN160 SP’08
Active well/substrate taps
Had to adjust well
S. Reda EN160 SP’08
Select for taps
S. Reda EN160 SP’08
Polysilicon
S. Reda EN160 SP’08
Metal 1
S. Reda EN160 SP’08
Contacts (to active)
S. Reda EN160 SP’08
Contacts to poly
S. Reda EN160 SP’08
Contacts to poly
S. Reda EN160 SP’08
Piece of metal1 for input pin
S. Reda EN160 SP’08
Via1 from metal1 to metal2
S. Reda EN160 SP’08
Add little metal2 for output pin
S. Reda EN160 SP’08
Design Rule Checker (DRC) verifies that
your layout does not violate any rules
ignore density warnings if they show up
error
S. Reda EN160 SP’08
Design cosmetics
Translate your design to the origin
S. Reda EN160 SP’08
Label your inverter pins
Make sure you are on the right layer
When you label pin, you can select a region (not just point)
S. Reda EN160 SP’08