ECEN 454 Digital Integrated Circuit Design Lab9

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Change to your tutorial/db/ directory.Enter TOP_attributes.db in the File Name field to save the file to db directory.Check the Save All <strong>Design</strong>s in Hierarchy option.Till now, the entire design hierarchy is loaded and the designs view displays the 13 icons for thealarm clock design. Note that always save your design work in case your machine is down.2. Set attributes for the designAttributes are values set on a design that control or affect the optimization of the design. Forexample, attributes can specify the operating environment of the design, the constraint goals ofoptimization, as well as many other design parameters.g) Select TOP design.Click the down-level-button (down arrow on the left).Click the symbol view button (the 2nd button on the left).h) Set the Drive Strength on Input PortsAssume that all input ports except CLK have drive strength 0.08. Units are determined by thetarget library.Use left mouse button to select the input port ALARM. Use the middle mouse button to selectthe other input ports, except CLK. Select “Attributes->Operating Environment->DriveStrength”. The Drive Strength window displays. Type 0.08 in the Rise field. The Same Riseand fall option is checked by default.Click Apply to set the values.Click Cancel to dismiss the Drive Strength window.Set the Drive Strength for CLK to be that of pin Z of the driver cell B4I in the target library.Select CLK.Select “Attributes->Operating Environment->Drive Strength”.Enter “drive_of (class/B4I/Z)” in the Rise field. The Same Rise and fall option is checked bydefault.Click Apply to set the values.Click Cancel to dismiss the Drive Strength window.i) Set the Load on Output Ports
Load values are used to model the capacitive load on the output ports of the constrainedmodel.SPEAK_OUT drives a load of five inverters. The load of each invertor is 1.5(load of cell IVA,pin A in the target library). So the load value for SPEAK_OUT is calculated as (1.5 * 5=7.5).Loads for DISP1 and DISP2 are 3.Select the SPEAKER_OUT port.Select “Attributes->Operating Environment->Load”.Replace the contents of the capacitive load field with load_of (class/IVA/A) * 5. Leave aspace before and after the asterisk (*).Click Apply.Click Cancel to dismiss the Load window.Repeat the above steps to set capacitance load value on DISP1 and DISP2 to be 3.j) Set the Wire LoadSelect TOP.Select “Attributes->Operating Environment->Wire Load”.Select 10x10(class). As defined in the library file, 10x10 corresponds to a die size of 1mm x1mm.Click Ok.k) Set the Operating ConditionsOperating conditions are the temperature, process and voltage in which the design operates.The target library defines operating conditions. Library vendors define default operatingconditions, which can differ from one vendor to another.Select “Attributes->Operating Environment->Operating Conditions”. The operatingconditions window appears and lists operating conditions from the target library.Select WCCOM (class) in the Operating conditions window. This is the worst-casecommercial operating condition defined in the target library.Click Ok.l) Save the design and your attribute settingsSelect “File->Save As”.Change to your tutorial/db/ directory.
Page 3: Detail procedures:a) Analyze the bo
Page 7 and 8: The design errors window appears.d)
Page 9 and 10: f) Set Execute In to Background.g)
Page 11 and 12: z) Click Cancel to close the Net Lo

ECEN 454 Digital Integrated Circuit Design Lab9

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