Routing algorithms for programmable logic device design and manufacturing test development

Abstract

A Computer Aided Design (CAD) tool consisting of two new interconnect network routing algorithms is developed. It was developed to assist in manufacturing test development for any Programmable Logic Device (PLD) such as Complex Programmable Logic Devices (CPLDs) and/or Field Programmable Gate Array (FPGA) devices which utilize any interconnect network structure whose definition/connectivity and control can be described in a presented manner. The CAD tool utilizing the new routing algorithms supports manual and semiautomatic explicit, non-explicit, and net routing and was extensively tested on the interconnect networks of the Cypress Delta39K/sup TM/ series CPLD for the purpose of manufacturing testing of the programmable interconnect networks within the device as well as all programmable logic functions of the device. The two routing algorithms were developed and experimentally proved to work correctly with the best one chosen based on both theoretical and experimental complexity analysis and the particular routing scenario to be solved. The resultant routing CAD tool will produce the configuration bits necessary to program or configure PLD devices for the extensive tests that must be applied to ensure that the manufactured PLDs are defect-free. The router CAD tool can also be extensively used in the verification of the design process of PLDs as verified via experimental testing.