This document discusses the simulation of single layer and multilayer artificial neural networks using Verilog. It begins with an introduction to artificial neural networks and their application in VLSI circuit fault diagnosis. It then provides details on the algorithm and design methodology for simulating a single layer neural network to model an AND gate, showing the calculation of error over iterations in Matlab and time taken using Verilog code. For a multilayer network modeling an XOR gate, it similarly discusses the backpropagation algorithm, showing error reduction over iterations in Matlab and time taken using Verilog. It concludes that neural networks can help minimize time to find faults in digital circuits.