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FPGA Fused Multiply Add (FMA)

“The operation fma(x, y, z) computes (x · y ) + z as if with unbounded range and precision, rounding only once to the destination format.”

(taken from IEEE 754-2008)

Here we try to come up with an efficient operation that makes use of Partial Product Reduction Trees (PPRT) to speed up multioperand additions.

These are implemented on a Intel DE1-SoC board that comes with a Cyclone V FPGA.

Hardware Design (FPGA)

This repository is a Quartus Prime project that is checked in. We are currently using version 16.1. You can find it on the Altera/Intel FPGA website.

Launch soc_system.qpf to open the project in Quartus.

ghrd_top.v is a generated reference design a.k.a Golden Hardware Reference Design that has taken care of lots of boilerplate Verilog/VHDL. It is also our Top Level Entity.

Software (HPS)

In order for the FPGA to talk to the HPS system, we need to allow the components to communicate via a bridge. This is done through Qsys.

For this current implementation, we are only making use of the Lightweight HPS-to-FPGA bridge. It has a maximum of 32-bit data width.

The software implementation is done in C, and can be found in the software directory. This folder contains C source and header files necessary to make use of our hardware design from software.

Compilation

Compiling the C code in src/software is all done via a Makefile. cd into the software directory and run make to compile.

After compilation, copy the file to our board running any flavor of Linux and run it.

NOTE: You might run into permissions issue. Simply run as root:

chmod +x <location of binary>

Implementation

Still a work-in-progress. The general idea is to make use of a Wallace tree as a partial product reducer.