NNTP-Posting-Date: Fri, 10 Jan 2003 19:13:43 -0600
From: firstname.lastname@example.org (John Fields)
Subject: Re: Counter Skipping.....
Date: Sat, 11 Jan 2003 00:55:23 GMT
Organization: Austin Instruments, Inc.
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On Sat, 11 Jan 2003 00:17:43 -0000, "g0mem"
>"John Fields" wrote in message
>> On Fri, 10 Jan 2003 16:45:49 -0700, William
>> >Hello Everyone,
>> >The counter has 2 Eproms for which it has digits for 10's and 1's
>> >(0~99) It counts backwards, but the results are not linear. Every so
>> >often it Will skip like 51,50, 39, 38 etc. The enable for the first
>> >(tens) Eprom goes high for only 5 microseconds. I selected a CR time
>> >constant of 1us which consists of 100pf cap and 10k resistor, so that
>> >the Eprom will subtract 1 instead of 2. It's tied to the enable line
>> >in parallel and one side to ground. I tried setting the enable line
>> >high for only 2us in software, but the the tens counter doesn't
>> >subtract at all.
>> >Questions: The CR time constant, should it have a longer or shorter
>> >fall time for this counter? Should the CR time be longer or shorter
>> >than what I selected?
>> >Any help would be great
>> Well, you've got _me_ confused! I have no idea what you're using
>> for a counter, why the EPROM enable times matter or, as a matter of
>> fact, what on earth you're talking about. How about an explanation
>> of what your application is and a schematic? You'll need to post it
>> to a web page somewhere or to alt.binaries.schematics.electronic
>> since this a text-only newsgroup and a lot of servers will probably
>> reject it if you try to post it here.
>It got me confused to. What are the EPROMs for, dot-matrix character
It sounds like he may be trying to use registered EPROMS as state
machines to implement a down counter, but who knows?
Professional circuit designer