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From: lee@sed170.HAC.COM (John Lee )
Newsgroups: comp.sys.amiga.tech
Subject: Re: 8520 (CIA) timers
Keywords: 8520 CIA timer
Message-ID: <296@sed170.HAC.COM>
Date: 7 Jul 89 23:59:21 GMT
References: <12524@well.UUCP>
Reply-To: lee@sed170.UUCP (John Lee (ird))
Organization: Hughes Aircraft Co., El Segundo, CA
Lines: 22
Distribution:

In article <12524@well.UUCP> sjm@well.UUCP (Stephen Moehle) writes:
>I am using the 8520 chips to do some timing, and I am having one major problem.
>Nowhere can I find out what the period of time is that I am counting.  I am
>using the "count 02 pulses" mode, whatever that means.  That is the phrase
>used in the 1.1 Hardware Reference Manual.  Could some one please tell me how
>many microseconds one of these timer ticks is?  Thanks.
>
>Stephe
>{ucbvax,pacbell,hplabs}!well!sjm     or     sjm@well.sf.ca.usa
>"You heard the weirdo man.  What is truth?"

Sure.  The phase-2 clock is roughly 718 KHz, so each of the 8520 "ticks"
or phase-2 pulse has a period of 1 / 718 KHz or 1.39 microseconds.

--John
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