VLSI Layout using Microwind

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VLSI Layout using Microwind. Kishore C Acharya. Getting Microwind. Go to the website http://www.microwind.org Download the freeware version of the microwind in a Folder called microwind_source Unzip the files in a Folder called microwind_layout. Setting Up Technology File. - PowerPoint PPT Presentation

Text of VLSI Layout using Microwind

  • VLSI Layout using MicrowindKishore C Acharya

  • Getting MicrowindGo to the websitehttp://www.microwind.orgDownload the freeware version of the microwind in a Folder called microwind_sourceUnzip the files in a Folder called microwind_layout

  • Setting Up Technology FileLaunch the program microwind2.exe from the folder microwind2-7 within microwind_layout folderFrom File Menu-> Select Foundry Browse to Folder Micrrowind2-7 and open the file cmos06.rul On the Layout window at the Top left there is a ruler. The ruler should say 5 lambda and 1.5 micron

  • Creating your own rule fileIf the appropriate rule file is not available, you can create your own rule file: Using notepad open the file default.rul in microwind2-7 folderEdit appropriate parametersSave as a new fileNote: Oxide thickness is defined in l3tox within spice parameters

  • Suggested Directory TreeMain Directory C or DMicrowind_sourceMicrowind_layoutMicrowind2-7ee393_layoutContains all microwind filesAutomatically built during Unzip Contains all layout filesAnd special .rul filesContains microwind2,zip

  • Opening and Saving Layout FilesOpen: From File menu Select Open and Browse to the folder ee393_layout and open the appropriate .msk fileSave: From File Menu select Menu item Save as and save layout file in ee393_layout directoryYou must setup Technology Right after Launch before any work

  • Working with Layout NotesTo draw a transistor click on the transistor symbol in the Palette window. Select transistor type (PMOS or NMOS)Select the units in lambda and specify width in terms of lambdaDelete: select the Gun icon and either click on each color section or draw a border around the device

  • To Do LayoutSelect the appropriate trace e.g. poly, metal1, contact etc.Draw a rectangle by dragging the mouse and the appropriate trace will be drawn as you release the mouse button

  • Design rule checkerDuring layout process check if the component placements such as NMOS, PMOS transistors are correct.From the Analysis menu select the menu item Design Rule CheckerIf the placements are correct Checker will report No errorIf there are errors, checker will display them on the components in the placement windowClicking the mouse in the placement window will remove the error display

  • Well ContactsFrom Palette menu select contact (three bars next to transistor symbol)Select N+ to Metal contactPlace the contact on a Metal line over the N well (if needed extend the N well over the Vdd busRun design rule checker

  • Substrate ContactsFrom Palette menu select contact (three bars next to transistor symbol)Select P+ to Metal contactPlace the contact on a Metal line (ground bus) next to the NMOS transistorRun design rule checker

  • Metal to Metal ContactsFrom Palette menu select contact (three bars next to transistor symbol)Set Poly to Diff Contact selection to noneCheck () appropriate metal to metal contact (e.g. Metal 1 to Metal 2)Place the contact on the intersection of the two Metal lines Run design rule checker

  • Working with Layout Notes ContinuedRotate & Flip: From Edit Menu select menu item Flip or Rotate -> Flip or Rotation angleDraw a box around the objectMove: From Edit Menu select menu item Move or StretchDraw a box around the object and move the object by dragging the mouseclick on an edge of the object and stretch it by dragging the mouse

  • Working with Layout Notes ContinuedPan: From the tool bar use left, right top and bottom arrows for panning alternatively use the arrow keys from the keyboardMove stepwise: From Edit Menu select menu item Move Step By StepDraw a box around the object and move the object by clicking on the arrows that appears on the screen

  • Working with Layout Notes ContinuedDelete: From the menu bar select the gun symbol (Delete Some Layout)Method 1:Draw a box around the object to be deleted using the mouse and let go the mouse button Method 2:Place the mouse pointer on the object to be deleted and click the right button

  • Working with Layout Notes ContinuedZoom in: From the tool bar use Zoom in icon and then click on the Layout WindowZoom out: From the tool bar use Zoom out icon and then click on the Layout WindowOn the tool bar click on the draw box icon to stop Zoom operationTo Print: From the File Menu select Menu item Print Layout

  • Obtaining parasitic valuesPut the mouse on a section of the Layout (e.g. Metal lines, Gate connections etc) and click the right button of the mouse. From the displayed menu at the mouse point select the menu item Node PropertiesA new window called Navigator will be displayedRead the parasitic values displayed in the navigator WindowIf the parasitic values are not displayed click on Props Tab of the Navigator window

  • Some drawing & design rule helpMake width of all metal lines 4lMake spacing between two adjacent metal lines 6lWhen making contact between metal and polysilicon, build a 4l by 4l pad with polysilicon for connectionFor layouts needing many connections use Metal 1 for Horizontal lines and Metal 2 for vertical lines

  • Changing Layout displayTo BW LayoutFrom File Menu Select menu item ColorsFrom Colors submenu click on MonochromeFrom Colors Submenu White or Black back ground can be selected by clicking on White background To Color LayoutFrom File Menu Select menu item ColorsFrom the Colors submenu click on Color

  • Naming Nodes and Assigning ParametersSelect a node by double clicking on itRight click and select Text PropertiesType name of the (e.g. In, Vdd, Out etc.) node in the Label name boxSelect node type by clicking on the buttonEnter appropriate parametersFor observation in simulation click not in simulationObservable variable are shown in italicsClick on Assign buttonClick on Move icon and move name into the node by clicking on it

  • Assigning Virtual ComponentsFrom the Edit menu select menu item Virtual RLC Click on the R or L or C

  • Creating SPICE NetlistFrom File menu select menu item Convert InfoSelect SPICE netlist

  • About SPICE in MicrowindSPICE Model files are located in rule fileSupported Simulation TypeFrequency Sweep Analysis (Frequency vs. time)DC Analysis (Static Voltage vs. VoltageTransient Analysis (Voltage vs. time & Voltage,Current vs. time)Model Selection (Level 1, Level 3& BSIM)

  • Running SimulationIf default Vdd is not correct Set default voltage to desired voltage in rule file To find the variable in rule file search for vddSet Vdd = 5.0 for I/O & Vddh = 5.0 or 3.3 for core logicSelect Run Simulation from Simulate menu Select Simulation type from sub menuSetup simulation parameter in simulation dialog box that appears

  • Model & Parameter SelectionDefault model is level 3To use different model from simulate menu select using model then model type (Level 1 or BSIM) from submenuSimulation parameters (Model, voltage range, temperature etc.)can be setup by Selecting Simulation parameter menu item from Simulation Menu

  • Simulation Parameter SetupFor Transient Analysis (Voltage vs. time or Voltage, Current vs. time)Set to desired duration by clicking into the Time Scale dialog item (center right)For DC Analysis (Static Voltage vs. VoltageSet to desired voltage range by clicking into the X Scale dialog item (center right)Simulation could be repeated by clicking into Reset or more button

  • Getting Microwind2Go to the websitehttp://www.microwind.orgClick on the Hyperlink (Location: Top right) New: A book on CMOS design by J. Uyemura based on Microwind Click on the hyperlink (Location: Below the description of the book)Microwind 2.7 (lite version) Download the file in a Folder called microwind_sourceUnzip the files in a Folder called microwind_layout