CAD Tools Magic/IRSIM/SPICE 簡介

CAD ToolsMagic/IRSIM/SPICE簡介 Presenter：林郁翔 Rm 330 4/06/2001

Outline • Introduction • Magic – Layout Editor • IRSIM – Logic-level simulator for MOS circuits • SPICE – Transistor-level simulator for MOS circuits

Introduction Design Circuits Circuit-level Simulator SPICE Layout Tools Magic A extract verification C=A? Logic-level Simulator IRSIM C

Magic – Layout Editor

What is Magic? • A color painting tool? • Quite a bit about the nature of VLSI circuit layout • Additional operations • Built-in Design-Rule-Check (DRC) • Built-in Hierarchical circuit extractor • Some useful functions such as routing tools

How to Get Help? • Manual • Hard copies • Electronic files • postscript files available on workstation: • ~r89004/vlsi/magic_tutorial (tutorial files) • ~r89004/vlsi/magic_tutcells (example files for tutorial) • On-line help • >> :help subject

Running Magic • 在 Linux 中的 magic 及 irsim, 均需要將CAD_HOME 環境變數設到 /home/cad 目錄下, 也就是, 如果用的是 C Shell (csh, tcsh), 要加入下列兩行到 $HOME/.cshrc 中 setenv CAD_HOME /home/cad set path=($path $CAD_HOME/bin) • 可在shell檔內加上alias，例： alias magic 'magic -dX11 -T tsmc0p8_spdm' 則以後只要鍵入 magic iv 即可執行 • 在 Linux中執行 >> magic –dX11 –T tsmc0p8_spdm filename

The Box & the Cursor • Used to select things on the color display Mouse right button Mouse left button

Invoking Commands • Invoking Commands • Type “:”(colon) or “;”(semi-colon) to invoke command • Use macro • E.g. ‘u’ means “:undo”

Painting Commands • Basic Painting • :paint layers (color) • :erase layers • “ ^D ” (erase all layers underneath the cursor) • Use Mouse • Select or box what U would like to paint • Move to the color (layer) U would like to paint • Press middle button (or press left & right together if U use 2-button mouse)

Select Commands • If I mistake to take action… • :undo(u) • :redo(U) • Select • Move over the portion and type ‘s’ • Type ‘S’ to select more • Select area ‘a’ / select more area ‘A’ • Clear out the selection • ‘C’ or “:select clear”

Commands on selection • Command on selection • :delete d • :move q(l), w(d), e(u), r(r) • :stretch Q, W, E, R • :copy c • :upsidedown (vertically flip) • :sideway (horizontally flip) • :clockwise

Label Commands • Label • :label [ text [ position [ layer ] ] ] • Erase a label • Select it and delete it • Erase all labels • :erase labels • Labeling conventions • Vdd! GND! (important!!)

Other Commands • Save to files • :writeall • :save [ filename ] • Magic file format : *.mag • Utility Commands • :grid [spacing] • :zoom z / Z (zoom in/out) • Leaving Magic • :quit ( :q)

Advance Painting Commands(1) • More useful painting – wiring • :tool (macro ‘space bar’) • :tool box (return to box mode) • Painting steps: • Select the material you want to paint • Left click the material • Move the cursor and right click the path you would like to paint • Use middle click to place contact

Advanced Painting Commands(2) • Manipulating Subcells • :getcell (name) • :array xsize ysize • Cell Hierarchy • Expanding • x (expand) • X (overview) • Design Rule Checking • :drc why • :drc find

IRSIM – Logic-level simulator for MOS circuits

Function of IRSIM • Logic-level simulation (based on RC model) • Display simulation waveform • Differences from SPICE • IRSIM is an event-driven logic-level simulator for MOS transistor circuits. • SPICE is a circuit analysis tool for simulation of electrical circuits in steady-state, transient, and frequency domains.

IRSIM EXAMPLE • Follow the next steps: • Load layout file and extract in magic command .:load or4:extract • Convert .ext file to .sim file.ccsun> ext2sim or4.sim or4.ext • Construct command file for IRSIM.Use any text editor to edit command file *.cmd.

COMMAND FILE EXAMPLE ***************or4.cmd********************* h Vdd! l GND! vector INPUT a b c d clock Vdd! 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 V INPUT 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 R 1

Logic Waveforms 4. Execute IRSIM with *.sim and *.or4ccsun> irsim tsmc08.prm or4.sim -or4.cmd 5. Run analyze windowirsim> ana a b c d z 6. Analyzer window with simulation results will pop up.

ANALYZE WINDOW

SPICE – Transistor-level simulator for MOS circuits

Magic to Spice • Convert magic extracted files to spice net files ext2spice name.sp name.ext

SPICE • SPICE : Simulation Program with Integrated Circuit Emphasis • Developed by University of alifornia/Berkeley (UCB) and is largely used by VLSI design • Numerical Approach to Circuit Simulation • Circuit Node/Connections Define a Matrix

5 Vin 1 2 1 0 SPICE Example **********title********** .lib 'tsmc08.model' TT .option post .op .global vdd vss ** Circuit Description ** M1 2 1 5 5 PCH L=1um W=1um M2 2 1 0 0 NCH L=1um W=1um C1 2 0 50f *drain gate source substrate 1

SPICE Example(cont’d) ** Sources** Vin 1 0 DC +2.5V VDD vdd 0 DC +5V VSS vss 0 DC 0V ** Analysis Requests ** .DC Vin 0 5 0.1 .end

Output Waveform • >awaves

More about SPICE simulation • Timing analysis • .tran tincs tstop • Clock source：PULSE ( V1 V2 < Tdelay Trise Tfall Pwidth Period > ) • Sub circuit • Example:.SUBCKT INV IN OUTM1 OUT IN VDD 0 P L=0.5u W=WPM2 OUT IN 0 0 N L=0.5u W=WNR1 OUT 4 1K.ENDS INV

CAD Tools Magic/IRSIM/SPICE 簡介