[time-nuts] Frequency counter questions

[Chris Albertson]

Confusion comes about because there is a ton of on-chip hardware an
addition to the CPU.  An edge detector, prescaller and a few hardware
counters on the STM32.   So I said he'd likely not be actually counting in
software but just setting up the desired tiger condition, loading the
prescaler then letting it run for a gate interval and finally reading out
the count.     The hardware is good for some tens of MHz.  But you really
have to be careful in your programming to get this exactly right.  Easy to
by off by one.

The chip has all kinds of other devices that greatly off load the CPU for
example making PWM outputs.

But you are right, we don't know what the OP wants to do.  Is he a ham what
needs to monitor the output of a transmitter and is this HF or microwave.
We's need to know the real world use case in order to suggest a solution.



On Sun, Apr 23, 2017 at 12:48 PM, Bob kb8tq <kb8tq at n1k.org> wrote:

>
> >
> > Yes, But I assume he is not going to do the actual counting in software.
>
> Except that’s not what he *said* he was trying to do. Thus the confusion
> and attempt
> to clarify what he’s trying to do. We now have a half dozen people who are
> equally
> confused about the task and no further input from the only person who
> actually
> *knows* what he’s trying to do. If indeed you have registers and the like,
> then they
> are probably in an FPGA. If you already have an FPGA doing the high speed
> stuff,
> the need for the F7 is even more questionable. Yes it’s a $12 or so chip,
> what needs
> to be done can be done with a $2 chip. Not only is would it be cheaper. It
> likely
> would be faster and easier to get working.
>
> Bob
>
>
> > He will likely be using the CPU to set and read some registers and
> control
> > the user interface.
> >
> > The time stamping idea is not bad.  But today you do NOT need to "post
> > process".  Your little processor could do this in nearly real-time and
> > you'd have results on the screen in seconds.
> >
> >
> >
> > --
> >
> > Chris Albertson
> > Redondo Beach, California
> > _______________________________________________
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-- 

Chris Albertson
Redondo Beach, California