Orcad introduction

Introduction

OrCAD is a suite of tools from Cadence for the design and layout of printed circuit boards (PCBs). This tutorial covers version 9.2 of the OrCAD suite. This document will give you a crash course in designing an entire circuit board from start to finish. This will be a very small and simple circuit, but it will demonstrate the major concepts and introduce the tools behind completing a PCB design. After you have completed this tutorial, you will know all the steps needed to make PCBs using OrCAD. This is not, however, a guide to the inner workings of the OrCAD interface. You should use this document in conjunction with the online OrCAD help and tutorials.

The circuit you will design is shown in the figure below. The main component is a programmable logic device (PLD) from Xilinx . PLDs, as the name implies, are programmable devices that can be used for a variety of useful tasks, and it is useful to be familiar with using them. In this circuit, we will use the PLD to light up a 7-segment LED display that will be used as a counter. Also in the circuit: a power connector for a 9-volt battery, a header for general purpose IO, a pushbutton switch, a programming interface for the PLD, and some miscellaneous resistors and capacitors.

OrCAD really consists of two tools. Capture is used for design entry in schematic form. You will probably be already familiar with looking at circuits in this form from working with other tools in your university courses. Layout is a tool for designing the physical layout of components and circuits on a PCB. During the design process, you will move back and forth between these two tools.