megafunctions

Megafunctions are prebuilt, parameterizable hardware modules provided for use in FPGA designs, originally by Altera and now under Intel FPGA. They implement common functions such as memory blocks, multipliers, digital signal processing blocks, phase-locked loops, and various I/O interfaces, allowing designers to integrate complex functionality without writing RTL from scratch.

Megafunctions are instantiated within the design toolchain, typically via a wizard or by inserting HDL wrappers. Users specify parameters such as data width, depth, timing constraints, and device targets. The tools then generate a device-optimized implementation along with Verilog or VHDL wrappers for integration into the project.

Historically, the term referred to a family of IP blocks within the Quartus environment, often associated with the LPM (Library of Parameterized Modules) components and specialized modules. The MegaWizard Plug-In Manager was the common interface used to configure and generate these blocks. The generated blocks are designed to be efficient for the target FPGA device and come with documentation on timing and resource usage.

Since the acquisition of Altera by Intel, megafunctions have been rebranded and expanded under the Intel FPGA IP umbrella. The concept remains the same, though current products are typically referred to as IP cores or IP libraries, accessed through the Intel FPGA IP Catalog. Megafunctions (or their successors) continue to be distributed with Quartus and related design tools, with licensing varying by block and use case.

Examples of megafunctions include altpll (phase-locked loop), altdpram (dual-port RAM), and various DSP, FIFO, and memory-related modules.