Terasic De0-Nano, User Manual

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14. Press the Esc key or click an empty place on the schematic grid to cancel placing further
instances of this symbol.
15. Save your project regularly.

Adding a Megafunction to the Schematic
Megafunctions, such as the ones available in the LPM, are pre-designed modules that you can use in
FPGA designs. These Altera-provided megafunctions are optimized for speed, area, and device
family. You can increase efficiency by using a megafunction instead of writing the function yourself.
Altera also provides more complex functions, called MegaCore functions, which you can evaluate
for free but require a license file for use in production designs. This tutorial design uses a PLL clock
source to drive a simple counter. A PLL uses the on-board oscillator (DE0-Nano Board is 50 MHz)
to create a constant clock frequency as the input to the counter. To create the clock source, you will
add a pre-built LPM megafunction named ALTPLL.
1. Right click in the blank space in the BDF and select Insert > Symbol or click the Add Symbol
icon on the toolbar.
2. Click the Megawizard Plug-in Manager button. The MegaWizard® Plug-In Manager appears,
as shown in
Figure 6-19 .
Figure 6-19 Mega Wizard Plug-In Manager