Mentor Graphics Tutorial

EE610

Prepared by HIMANSHU & ANUJ

To start Mentor Graphicsright click on desktopclick on open terminalcshmkdir ~/mentor_designs

last command Required only for first time

To use Mentor Graphics

cshcd mentor_designssource /cad/Mentor_tools/ICFlow/2008.cshicstudio&

Mentor Graphics icstudio GUI will open

initially the screen will look like

• Click on File• Then New• Then Project• You will get following window

02

• Press Next button to continue• Give appropriate name to your project

03

• Again press the Next button• Now press ‘Open Library List Editor...’ button

04

• Then click ‘Edit Menu’ button• Select ‘Add MGC Design Kit...’ option• There select ‘/cad/Mentor_tools/ADK_3.1’

Then a row named ‘MGC_DESIGN_KIT’ will be added to the entries

• Now again press ‘Edit Menu’ button• Then select ‘Add Standard MGC Libraries’ then

more 5 libraries would be added to entries

• Now press ‘New Row’ button thrice to add 3 new rows & fill them as follows

• (you can add rows by browsing appropriate location upto ‘mgc_icstd_lib’ & then write name of perticular library)

MGC_IC_COMMLIB /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/mgc_ic_commlib

MGC_IC_COMMLIB_QS /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/mgc_ic_comm_qs

MGC_IC_COMMLIB_RF /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/mgc_ic_comm_rf

There must be 9 entries as followsMGC_DESIGN_KIT /cad/Mentor_tools/ADK_3.1

MGC_IC_GENERIC_LIB /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/generic_lib

MGC_IC_DEVICE_LIB /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/device_lib

MGC_IC_SOURCES_LIB /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/sources_lib

MGC_IC_VERILOG_LIB /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/mgc_ic_verilog

MGC_IC_MICROLIB /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/mgc_ic_microlib

MGC_IC_COMMLIB /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/mgc_ic_commlib

MGC_IC_COMMLIB_QS /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/mgc_ic_comm_qs

MGC_IC_COMMLIB_RF /cad/Mentor_tools/ICFlow/2008.2o/2008.2o_linux_x86_64/icflow_home/mgc_icstd_lib/mgc_ic_comm_rf

Press OK

Press ‘Next’Press ‘Open Settings Editor’There you must fill the entries as follows

Process File /cad/Mentor_tools/ADK_3.1/technology/ic/process/<technologyname>

DRC Rules File /cad/Mentor_tools/ADK_3.1/technology/ic/process/<technologyname>.rules

LVS File /cad/Mentor_tools/ADK_3.1/technology/ic/process/<technologyname>.calibre.rules

PEX Rules Files /cad/Mentor_tools/ADK_3.1/technology/ic/process/<technologyname>.calibre.rules

*Leave ‘SDL rules file’ entry empty*<technology name> are ami05(0.5µm),

tsmc018(180nm)

• Press ‘OK’• Then ‘Next’• Then ‘Finish’

• Now including the libraries is over• our screen will look like...

• Now we can built the circuit• To do this we have create new Library• Right click within Library space & select New

Library• Give appropriate name to the library & press

OK

• Select the created Library• Right click within the Cell area• Select ‘New Cell View’• Enter Appropriate cell name• To built the circuit, select View Type as

‘Schematic’• View Name would automatically become

‘Schematic’• Press ‘Finish’

• To place devices select ‘Library’ on side panel• Then ‘Device Lib’• Let us put 4-pin NMOS

• Now select the device, right click over it & click over word ‘Properties’ but not on arrow in front

• Select the entry ASIM_MODEL & change the value NCH to N

• Click apply• As per requirement we can also modify other

attributes of NMOS like W, L etc.• Finally press ‘OK’

• Similarly place other devices like PMOS• Also through its properties make its

‘ASIM_MODEL’ as P from PCH

• Place VDD, GND etc through Generic Lib inside libraries on side panel

• Various sources can be placed through Sources Lib

• The value of the source can be modified by selecting it, then right click on it, through properties

• The small branch at the side of circuit is to define VDD

• Press W to place the wire• Make appropriate connections

• Now we have to add ports• Ports are of 3 types- portin, portout, portbi• through ports only we can vary or sweep the

signal• Ports list available on left sidebar• Place portin wherever we need to apply input

signal• Place portout wherever we need to take

output• By default name of each port is NET

• To change the name of the port select the point on port, right click & select properties

• Give appropriate name to the port

• Now our circuit is ready for simulation

SIMULATION

• Click Simulation on right side panel• Press New Configuration• Select AMS_Simulation & press OK• Select default (if any other configuration

comes again press New Configuration and repeat the step)

• Press OK

• Now we have to include Library(model) using which we are simulating our circuit

• For this select ADK Sim Palette on right sidebar

• Select Library & include appropriate model file (level1 or BSIM3)

• Press OK• Again press Default Sim Palette

• Now we have to Force the Input ports• Forcing means applying appropriate input

signal to input port• Select ‘Forces’ from right sidebar & click

manager• Now select the name of port which you want

to force i.e. the ports to which we are applying input signals & select appropriate input signal

• set its attributes

• After correctly setting the appropriate attributes of the signal add the signal to Forces list by pressing add button

• Force will appear as...

• Now we have to set nature of analysis like AC, DC, Transient etc

• Click ‘Analyses...’ on right sidebar & select appropriate one

• Then click on setup to enter detail of analysis• Finally click ‘OK’

• For transient simulation we always put starting time as 0

• Keep Stop time as per the requrements• Max time step should be kept as low as

possible to get higher accuracy but this leads to more simulation time

• Now before simulating we should store our input & output signals

• Select Setup, the Outputs• Add all input & output signals to the list by

clicking add button

• Now we can initiate simulation• To initiate the simulation press button ‘Run

ELDO’

• To view waveforms select View Waves & click on New Window

• Select correct analysis type & appropriate signals

• We can also put grids & cursor for measurements

DC Analysis

• For DC analysis select DC from Analyses...• Click on setup• During DC analysis we can sweep any voltage

signal between two values with proper voltage steps

• In shown example input voltage of the inverter has been swept from 0V to 3.3V & we got the proper output

• Similarly simulate the circuit using ‘Run ELDO’ & observe the waveforms appropriately

• AC analysis basically provides the frequency response of the circuit

• For AC analysis we have to force the input signal as sinusoidal signal of appropriate magnitude

• Then we have to set the analysis as AC• While setup we need to specify start & stop

frequency• Also we need to specify input port (where

signal freq is varied) & output port where we saw the effect

• Similarly results are seen through View Waves

• To finish the simulation press End Sim button• Save your work• Close the icstudio• Then type exit in the terminal & press enter• Again type exit & press enter