Specifications

CHAPTER 2: DESIGN ENTRY
USING ALTERA MEGAFUNCTIONS
ALTERA CORPORATION INTRODUCTION TO QUARTUS II ■ 47
Using Altera Megafunctions
Altera megafunctions are complex or high-level building blocks that can be
used together with gate and flipflop primitives in Quartus II design files.
The parameterizable megafunctions and LPM functions provided by Altera
are optimized for Altera device architectures. You must use megafunctions
to access some Altera device-specific features, such as memory, DSP blocks,
LVDS drivers, PLLs, and SERDES and DDIO circuitry.
You can use the MegaWizard Plug-In Manager (Tools menu) to create
Altera megafunctions, LPM functions, and IP functions for use in designs in
the Quartus II software and EDA design entry and synthesis tools. Table 3
shows the types of Altera-provided megafunctions and LPM functions that
you can create using the MegaWizard Plug-In Manager.
To save valuable design time, Altera recommends using megafunctions
instead of coding your own logic. Additionally, these functions can offer
more efficient logic synthesis and device implementation. It is easy to scale
megafunctions to different sizes by simply setting parameters. Altera also
provides AHDL Include Files and VHDL Component Declarations for both
Altera-provided megafunctions and LPM functions.
Table 3. Altera-Provided Megafunctions & LPM Functions
Type Description
Arithmetic
Components
Includes accumulators, adders, multipliers, and LPM arithmetic
functions.
Gates Includes multiplexers and LPM gate functions.
I/O Components Includes Clock Data Recovery (CDR), phase-locked loop (PLL),
double data rate (DDR), gigabit transceiver block (GXB), LVDS
receiver and transmitter, PLL reconfiguration, and remote
update megafunctions.
Memory Compiler Includes the FIFO Partitioner, RAM, and ROM megafunctions.
Storage Components Memory and shift register megafunctions, and LPM memory
functions.