Document Details

Uploaded by Deleted User

Universitat Rovira i Virgili

Jean-Pierre Deschamps

Tags

sequential circuits digital circuits electronics computer science

Summary

This document provides information about sequential circuits, including motivation and examples. It also discusses the concept of sequential systems and memory needed for these systems.

Full Transcript

5.1 SEQUENTIAL CIRCUITS Jean-Pierre Deschamps University Rovira i Virgili, Tarragona, Spain 5.1 Motivation Most digital system specifications cannot be implemented by combinational circuits because the value of...

5.1 SEQUENTIAL CIRCUITS Jean-Pierre Deschamps University Rovira i Virgili, Tarragona, Spain 5.1 Motivation Most digital system specifications cannot be implemented by combinational circuits because the value of an output signal could be a function of  (not only) the value of the input signals at the same time,  (but also) the value of the input signals at preceding times. Example: vehicle access control system. Input signals:  entrance request,  gate lower and upper positions,  vehicle present within the gate area, Output signals:  motor control (on/off, up/down). 2 5.1 Motivation The values of the signals that control the motor depend on the sequence of events:  entrance request,  open the gate,  wait for upper gate position,  wait for clear gate area,  wait for lower gate position. A new entrance request is not attended until this sequence of events is completed. Conclusion: Some type of memory is necessary. 3 5.1 1. Sequential systems Digital circuits with memory:  Output values at time t depend on input values at times t, t-1, t-2, etc.  Able to generate sequences.  Able to detect sequences. Example of sequence detection: implement a circuit that detects the following sequence: 1557. if x(t-3) = 1 and x(t-2) = 5 and x(t-1) = 5 and x = 7 then y

Use Quizgecko on...
Browser
Browser