Verilog Loop Unrolling, Module Generation, Part-Select and Arithmetic Right Shift Support in Odin II

Abstract

Verilog is a hardware description language (HDL) that supports the specification of hardware circuitry and control logic for production, simulation and testing. The subset of the specification used for production is called synthesizable. Verilog-to-Routing (VTR) is a Computer-Aided Design (CAD) flow. It transforms synthesizable Verilog into a placed and routed configuration for a Field Programmable Gate Array (FPGA) architecture specified in XML. The front end of the VTR CAD flow is Odin II. Odin II parses Verilog files and uses them to create a netlist consisting of inputs, outputs, nodes, and connections. Odin II is an open-source research project, and full Verilog language coverage is a work in progress. This work extends Odin II's Verilog support to files containing the arithmetic right shift operator (>>>) and both the + : and - : part-select operators. It also adds support for simple for loops, while loops and loop-based module generation. Dynamic looping constructs are not synthesizable, so all looping constructs are processed before the netlist is generated. This paper will present the missing language features that were implemented, the scope of their implementation, the architecture of the solution, testing and finally the efficiency of the contributions.