Asee peer logo

A Case For Teaching Mixed Logic In Digital Design

Download Paper |

Conference

2001 Annual Conference

Location

Albuquerque, New Mexico

Publication Date

June 24, 2001

Start Date

June 24, 2001

End Date

June 27, 2001

ISSN

2153-5965

Page Count

8

Page Numbers

6.6.1 - 6.6.8

Permanent URL

https://peer.asee.org/8983

Download Count

775

Request a correction

Paper Authors

author page

David Livingston

Download Paper |

Abstract

An important aspect of any logic design problem is an easy and direct design method which results in properly documented components; i.e., schematics, expressions, truth tables, etc., which accurately convey the designer’s original thought process. The mixed logic approach, which meets the above requirements, is proposed as a method to be taught in digital design courses. To understand mixed logic, the concepts of positive and negative logic and assertion levels must first be defined. Positive logic is defined as a high voltage level representing a logic 1 and a low voltage level representing a logic 0. Negative logic is the reverse, i.e., a low voltage level represents a logic 1 and a high voltage level represents a logic 0. Assertion levels determine whether a net or signal line in a digital circuit is to be interpreted as positive logic or negative logic. A negative logic assertion level is called active low and is represented by the presence of bubbles on the net in the schematic and a .L suffix on the logic variable. A positive logic assertion level is called active high and is represented by the absence of bubbles on the net in the schematic and a .H suffix on the logic variable. Mixed logic is the use of both positive and negative logic representations in a digital circuit design.

Livingston, D. (2001, June), A Case For Teaching Mixed Logic In Digital Design Paper presented at 2001 Annual Conference, Albuquerque, New Mexico. https://peer.asee.org/8983

ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2001 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015