MiniBit: Bit-Width Optimization via Affine Arithmetic
Dong-U Lee, Altaf Abdul Gaffar, Oskar Mencer and Wayne Luk
[Design Automation Conference, July 2005]
 
abstract.

MiniBit, our automated approach for optimizing bit-widths of fixed-point 
designs is based on static analysis via affine arithmetic. We describe 
methods to minimize both the integer and fraction parts of fixed-point 
signals with the aim of minimizing circuit area. Our range analysis technique 
identifies the number of integer bits required. For precision analysis, we 
employ a semi-analytical approach with analytical error models in conjunction 
with adaptive simulated annealing to find the optimum number of fraction bits.
Improvements for a given design reduce area and latency by up to 20% and 12% 
respectively, over optimum uniform fraction bit-widths on a Xilinx Virtex-4 
FPGA.