Z-80

Z80 Family CPU Peripherals
User Manual
UM008101-0601

ZiLOG Worldwide Headquarters • 910 E. Hamilton Avenue • Campbell, CA 95008 Telephone: 408.558.8500 • Fax: 408.558.8300 • www.ZiLOG.com

Z80 CPU Peripherals User Manual

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This publication is subject to replacement by a later edition. To determine whether a later edition exists, or to request copies of publications, contact:ZiLOG Worldwide Headquarters 910 E. Hamilton Avenue Campbell, CA 95008 Telephone: 408.558.8500 Fax: 408.558.8300 www.ZiLOG.com

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Document Disclaimer
©2001 by ZiLOG, Inc. All rights reserved. Information in this publication concerning the devices, applications, or technology described is intended to suggest possible uses and may besuperseded. ZiLOG, INC. DOES NOT ASSUME LIABILITY FOR OR PROVIDE A REPRESENTATION OF ACCURACY OF THE INFORMATION, DEVICES, OR TECHNOLOGY DESCRIBED IN THIS DOCUMENT. ZiLOG ALSO DOES NOT ASSUME LIABILITY FOR INTELLECTUAL PROPERTY INFRINGEMENT RELATED IN ANY MANNER TO USE OF INFORMATION, DEVICES, OR TECHNOLOGY DESCRIBED HEREIN OR OTHERWISE. Devices sold by ZiLOG, Inc. are covered by warranty andlimitation of liability provisions appearing in the ZiLOG, Inc. Terms and Conditions of Sale. ZiLOG, Inc. makes no warranty of merchantability or fitness for any purpose Except with the express written approval of ZiLOG, use of information, devices, or technology as critical components of life support systems is not authorized. No licenses are conveyed, implicitly or otherwise, by this document under anyintellectual property rights.

UM008101-0601

Disclaimer

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Table of Contents
Counter/Timer Channels

CTC Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 CTC General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 CTC Architecture . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Structure of Channel Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Interrupt Control Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 CTC Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .9 Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 CTC Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 CTC Counter Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..16 CTC Timer Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 CTC Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Loading The Channel Control Register . . . . . . . . . . . . . . . . . . . .19 Loading The Time ConstantRegister . . . . . . . . . . . . . . . . . . . . . .22 Loading The Interrupt Vector Register . . . . . . . . . . . . . . . . . . . . .22 CTC Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 CTC Write Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .24 CTC Read Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 CTC Counting and Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 CTC Interrupt Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27...