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MICROPROCESSOR CONTROL CLOCK

IP.com Disclosure Number: IPCOM000005433D
Original Publication Date: 1980-Aug-01
Included in the Prior Art Database: 2001-Oct-10
Document File: 1 page(s) / 45K

Publishing Venue

Motorola

Related People

Roland Schwarz: AUTHOR

Abstract

The novelty of this clock is the use of only up counters. When setting the clock, it is possible to either increment or decrement minutes and hours with only slightly more hardware.

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MOTOROLA Technical Disclosure Bulletin Vol. 1 No. 1 August 1980

MICROPROCESSOR CONTROL CLOCK

By Roland Schwarz

DESCRIPTION

The novelty of this clock is the use of only up counters. When setting the clock, it is possible to either increment or decrement minutes and hours with only slightly more hardware.

In normal operation, the clock signals HSET and MSET are at state "o", transistors Tl and T2 are "ON", transistors T3 and T4 are "OFF" and the clock counts seconds, minutes and hours.

   To make a minute set, the signal MSET is at a "1" state causing the second counter to be reset, tran- sistors Tl, T2 and T3 to be "OFF" and transistor T4 to be "ON". Pulses coming from the "Clock set" are counted in the minute counter, the output of which is decoupled from the hours counter by "OFF" tran- sistor Tl. To increment one minute, one pulse is needed (coming from the processor). To decrement one minute, fifty nine pulses are needed (from the processor). When minute set is completed, signal MSET goes "0" and the clock is working normally.

   To make an hour set, the signal HSET is at "1" causing transistors Tl, T2, T4 to be "OFF" and tran- sistor T3 to be "ON". Seconds are counting normally but minutes are not counted. Pulses coming from "Clock set" are inputting in the hours counter. To increment one hour, one pulse is needed. To decrement one hour, twenty-three pulses are needed. When hour set is finished, signal HSET goes to "0".

0 Motorola, Inc. 1980 40

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