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SubjectE & Q timing on M6809 Reply to this message
Posted bysellenoff
Posted on08/09/04 06:15 PM



Was wondering if someone could help me understand how to calculate the timing of these 2 signals from the 6809.

Assuming the external crystal is set to drive the 6809 @ 8Mhz (which i believe is the top speed the chip can go - on the 68B09), what would the frequency of the E & Q lines be?

The hardware i'm looking at uses E to pulse a 4020 counter which eventually toggles the FIRQ of the 6809, and obviously I'm trying to calculate the correct freq. to generate the firq.

I've looked over the 6809 datasheet and just don't really follow it. I've never been good with timing in general, and those datasheets are not written to be easily understandable unless you already get the concept! :)

So if someone could explain, not only the answer, but how I could have derived the answer from looking at the datasheet, it would be greatly appreciated..

Thanks
-Steve



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Entire Thread
Subject  Posted byPosted On
.E & Q timing on M6809  sellenoff08/09/04 06:15 PM
.*Sounds suspiciously like a homework question :) *nt*  Bart T.08/09/04 11:55 PM
..*Re: Sounds suspiciously like a homework question :) *nt*  sellenoff08/10/04 12:22 PM
...*Re: Sounds suspiciously like a homework question :) *nt*  Bart T.08/10/04 09:12 PM
....*Re: Sounds suspiciously like a homework question :) *nt*  sellenoff08/10/04 11:56 PM
...*Re: Sounds suspiciously like a homework question :) *nt*  Riff08/10/04 08:21 PM
....*Re: Sounds suspiciously like a homework question :) *nt*  sellenoff08/10/04 11:53 PM