CADENCE
Chintan Trehan
06/27/06
IC Design Flow
Steps
CAD Tools
Process information
Define System Specs
System-Level Design
MATLAB or other
math tools
Circuit-Level Design
Schematics drawer &
CKT simulator-SPICE
Physical level Design
Layout verification
Submit to Foundry
Layout drawer, Design
Rule Checker (DRC), &
Netlist extractor
Device models
Technology file,
DRC, extraction files
Layout vs. schematics (LVS) Technology file,
checker, SPICE for post
Device models
simulation
Read the Process
Orbit 2μm N-Well DPDM Process
Manufacturer
Minimum gate length
Latest CPU90nm(0.09μm)
CMOS implementation approach
P-well (obsolete), N-well,
Twin-well
Numbers of layers of ploy and metal
Standard CMOS – Single layer of poly
Analog/mixed-signal – Double layers of polys
Ex: DPQM - Double-Poly Quadruple-Metal
Using Exceed
Server Name : ees.ee.ttu.edu
Can be accessed using


Exceed in PCs
Remote logon in Sun Workstations
Using Exceed:
Hummingbird Connectivity 9.0 
Exceed  Exceed XDMCP
Broadcast
Choosing the server
Sun Workstations
Options - Remote
Logon --> Choose
“ees”
Note down the name
of the host.
ees-{129.118.19.64}
*Username – first
letter of your first
name and first five
letters of your last
name
Opening a Shell:
Choose
“Hosts This host”
Display settings for Sun
Workstation users:
setenv DISPLAY hostname:0. 0.
•On a shell prompt:
Type –”who am I” (lists hostname)
•Windows command prompt
ipconfig
setenv DISPLAY hostname:0. 0.
Accessing CADENCE
cp -r ~ctrehan/cad_usr .
Need to copy these
cp cad_usr/.cshrc .
files in your home dir
cp cad_usr/.cdsenv .
cp cad_usr/.simrc .
cp cad_usr/display.drf .
Logout after copying files and login
commands

‘icfb &’ – front-to-back IC
Instructions for using a particular tool is available in
the documents.

Some tools may require additional environmental settings.
Settings
All settings are done in


.cshrc (c-shell), .login (born-shell)
cds.lib – cadence library path
To check current settings

Shell prompt – type ‘env’ or `setenv’
UNIX OVERVIEW
MultiUser and MultiTasking OS
3 MAIN LAYERS
 KERNEL

Allocates resources and schedules
programs
 SHELL

Interprets commands and passes to kernel
 UTILITY PROGRAMS

File mgmt, Process mgmt , User mgmt
DIRECTORY
ABBREVIATIONS



Home
(~)
Current (.)
Parent
(..)
COMMANDS
 pwd (print working directory)
 ls
( Listing the contents of a directory)
 Options
( -Fi , -l , -al , - R )
 mkdir
 rmdir
 cd ( change directory)
Program Related
Each program is a process

pid , priority level
COMMANDS



ps (list process ids)
kill (send signal e.g. kill -9 pid)
& (background)
FILE HANDLING
COMMANDS





cp
mv
rm
cat
lp
( to copy a file)
( to move a file)
( to remove or delete a file)
( to catenate a file)
( to print a file)
File Permissions
Read (r)
Write (w)
Execute or Search (x)
COMMAND

chmod mode filename
 user
r w x
group
rwx
others
rwx
GENERAL COMMANDS
man ( Manual or help)
answerbook2
alias (add alias rm-i rm in .cshrc)
su
(switch user)
clear (clear screen)
df –k (disk free space)
grep (global regular expression print)
passwd (change the password)
vi (editor)
Inverter Schematic and
Simulation
Invoke ic front-to-back

icfb &
select ToolsLibrary Manager…… to
open Library Manager
{ If cadence setting are correct it’ll
automatically open }