# jIIR2HW
This repository contains scripts and julia packages that permit to design second-order IIR filters for multiplierless hardware.
**Context**: multiplierless implementations of products by constants using shift-and-add architectures.
**Problem**: determine the coefficients of an IIR filter in fixed-point arithmetic such that the total cost of the shift-and-add architecture is minimal in terms of number of adders.
**Techniques**: our approach is based on a formalization of the problem as an instance of a Mixed Integer Linear Programming problem, which is subsequently solved using a third-party solver.
**Input**:
* frequency specifications
* wordlength
**Output**:
* filter coefficients
* adder graph structure for the optimal solution
**Guarantees** (in case of successful exit):
* optimality of the proposed solution
* a posteriori validation of frequency specifications
**Options**:
* bounded/unbounded adder depth
* avoid internal shifts in the adder graph structure