4.5 Assign gate delay

After you create the schematic for your design, you might want to assign gate delay for later simulation for timing analysis. The two zeroes beside each gate on the schematic indicate its output rising and falling delay in nanoseconds.

To assign 3ns rising and falling delay to each gate:

  1. From the main menu bar:

    2. Setup -> Select Filter...

    The dialog box shown below will appear. Click on Clear All. Select Properties only. Then click OK

    Fig 4-5. Change select filter.

  2. Select the two 'zeroes' beside the gate.
  3. Select 'TEXT' on the right hand side schematic palette. The palette will be refreshed.
  4. Select 'CHANGE VALUE' on the palette. A dialog bar will appear on the bottom. Enter 3 in the new value box for rising delay and click OK. The zero beside the gate will become '3'.

    5. Fig 4-6. Enter gate rising delay.

  5. Also enter 3 in the new value box for falling delay and click OK.

    6. Fig 4-7. Enter gate falling delay.

    The gate will look like:

    Fig 4-8.Assign delay to gate.

  6. Repeat the steps to change all gates' delay.

click here to go back to Index:

4.6 Framing the Schematic

Note: Adding a frame to your design is not a must in schematic entry.

There are two types of ready-to-use borders available in Design Architect, one is the MGC border and the other is the ANSI border.

  1. To add sheet border, select from the main menu bar:

    2. Edit -> Add Sheet Border -> ANSI Std ...

    An 'Add ANSI Sheet Border' dialog box will prompt for sheet size.
  2. Select the proper border size for your schematic, then click on 'OK'.
  3. A dialog box will appear. Enter the sheet information in the dialog box.
  4. If the schematic doesn't fit into the border, click 'UNDO' on the right side palette. Try a bigger one.

click here to go back to Index:

5. Check/Save the sheet

  1. The schematic you have created needs to be checked for connection errors before it is saved into a file. To do this,

    2. Check -> Sheet

  2. A 'Report' window will pop-up indicating the errors and warnings in the schematic. If any errors are reported, go back to your schematic and correct them otherwise go to the next step.

    3. Fig 5-1. Check the sheet and report.

  3. In the schematic window,

    4. File -> Save Sheet

click here to go back to Index

6. Generate Symbol

  1. After your schematic is completed, you may want to create a block symbol to represent this circuit. This symbol can be used in other schematics to perform the same function as this circuit, and you do not need to draw the same circuit again.
  2. Make sure that the schematic is checked and saved before making the symbol. To generate a symbol, select:

    3. Miscellaneous -> Generate Symbol...

    from the pull-down menu bar.
  3. Accept all the defaults by clicking 'OK' in the 'Generate Symbol' dialog box . A 'Symbol' is created automatically and is displayed in a new window.

    4. Fig 6-1. Generated symbol.

  4. Edit symbol if necessary. Use the same skill as in editing the schematic.
  5. From the pulldown menu bar, select

    6. Check -> With Defaults

    A report window indicating the errors and warnings in the symbol will pop-up. Correct the errors, if any.
  6. To save the symbol, select

    7. File -> Save Symbol -> Default Registration

    from the pull-down menu bar. You can now use this symbol in other schematics.

    Note:There might be some warnings as you check a newly created symbol. Save it and check that symbol again. If no warnings and errors, SAVE IT ONCE AGAIN.

  7. To use this symbol in other schematics, select 'CHOOSE SYMBOL' from the right hand side palette. Select the component you need, then click 'OK'. The symbol will appear at your cursor. Click in your work sheet at the desired location to place it .

click here for the next Section:

click here to go back to Index