Full-Custom Analog IC Design using Cadence DFII Virtuoso/Assura

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Symbols can be created manually by choosing the Composer-Symbol tool when creating a newcellview, then drawing the shapes and pins. However, it is also possible and much moreconvenient to have them generated automatically. A square box with pins is generated, that canthen be modified if wanted – it provides a good starting point. From the Schematic Editor menu, choose Design→Create Cellview->From Cellview. In the first form coming up, all options should be set correctly. Press Ok. In the second form, you get a chance to specify the location of the pins on your symbols. It iscommon to have input pins on the left, output pins on the right, and power/ground pins on thetop and bottom of the symbol. When you are done, press Ok. Do any changes you like to your symbol, then Check and Save it.3.5. CREATING A HIERARCHICAL CIRCUITIn the following steps, you will create the circuit schematic for a 4-to-1 multiplexer. You willfirst create the schematic for a 2-to-1 multiplexer using standard cells, then use this cell to createthe 4-to-1 multiplexer in a hierarchical manner. Create a new schematic in your VLSITP library. Name it DiffPair2. Draw the schematic as shown on figure 6. Use the DiffPair subcircuits from the VLSITP library..Figure 6 - The circuit schematic of two differential pairs10/23
When you are done, Check and Save your schematic. Correct any errors or warnings, until nomore are reported. Create a symbol for the DiffPari2. Create another new schematic in your VLSITP library. Name it ADC2.Figure 7 - The 2-bit ADC circuit schematic Draw the schematic as on figure 7, using your own ADC2 symbol. Create a symbol for the 2-bit ADC.Checkpoint Please call an assistant and show him/her that you have reachedthis point before working on further stepsVisaMoving up and down the hierarchyNow that you have designed a hierarchical schematic, you can experience moving up and downthe hierarchy. Open the ADC2 schematic. Select one of the instances of your ADC2 cell. Choose Design→Hierarchy→Descend Edit or press Shift+e. You will be prompted to select aview: choose the schematic view. The current schematic will be changed to DiffPair2. To return up the hierarchy to ADC2,choose Design→Hierarchy→Return or press Ctrlt+e.11/23
Page 1 and 2: LABORATOIRE DE SYSTEMES MICROELECTR
Page 3 and 4: Figure 1 - The CIW (Command Interpr
Page 5 and 6: Creating an new library Using the l
Page 7 and 8: Choose Add→Instance from the menu
Page 9: then drag the inverter to a new loc
Page 13 and 14: will provide the zero reference vol
Page 15 and 16: Figure 10- DC simulation setupWorki
Page 17 and 18: All available layers and their rela
Page 19 and 20: step involved design rules are list
Page 21 and 22: Figure 16 - Example for error in la
Page 23: Figure 20- Set up for post-layout s

Full-Custom Analog IC Design using Cadence DFII Virtuoso/Assura

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