Step 5: Enter a Megafunction Symbol

The next symbol you need to enter is a multiplier that is a variation of the lpm_mult megafunction. You can use the MegaWizard™ Plug-In Manager to enter this symbol. The MegaWizard Plug-In Manager allows you to create (or modify) design files that contain custom variations of megafunctions. These custom megafunction variations are based on Altera-provided megafunctions, including Library of Parameterized Modules (LPM) functions. The MegaWizard Plug-In Manager runs a wizard that helps you specify options for customization easily. The wizard prompts you about the values you want to set for parameters and which optional ports you want to use. Once the wizard generates the multiplier variation, you can instantiate it in the design file.

To enter a mult symbol generated by the MegaWizard Plug-In Manager, follow these steps:

  1. Double-click an empty space in the Block Editor window. The Symbol dialog box appears automatically.

  2. In the Symbol dialog box, click MegaWizard Plug-In Manager. The first page of the MegaWizard Plug-In Manager appears.

    3. Show Me

    MegaWizard Plug-In Manager Page 1

  3. In the first page of the MegaWizard Plug-In Manager, make sure Create a new custom megafunction variation is selected and click Next.

  4. Under Which megafunction would you like to customize?, click the + icon to expand the arithmetic folder, and then select LPM_MULT.

  5. Specify the following responses to the remaining wizard prompts:

    6. Wizard Prompt: Response:
    Which device family will you be using? APEX20KE
    Which type of output file do you want to create? Verilog HDL
    What name do you want for the output file? d:\qdesigns\fir_filter\mult.v
    How wide should the 'dataa' input bus be? 8
    How wide should the 'datab' input bus be? 3

  6. To accept the defaults for the remaining questions and generate the symbol, click Finish. A preview of the new symbol appears in the Symbol dialog box.

  7. Click OK. An outline of the mult symbol is attached to the pointer.

  8. To place the symbol, click the location you want the mult symbol to appear in the Block Editor window.

  9. Choose Save (File menu).


To continue the tutorial, proceed to Step 6: Arrange the Blocks, Primitives, and Megafunction.