ARMweb clock out

Questions on other types of hardware and getting it talking to the ARM CPU
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YahooArchive
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Joined: Fri Oct 19, 2012 5:11 am

ARMweb clock out

Post by YahooArchive » Tue Dec 04, 2012 2:18 am

> I see that on the ARMWeb there is a clkout pin from the en28j60 chip.
> I measured the freqency at 6.25MHz (the default value). Do you know
> of any reason why I should not hook up to it? Does this frequency
> change during operation at all?

We do not use that for anything, so it will remain the default.
You're on your own for trying to reprogram that, you might be able to
do by disabling interrupts to keep TCPIP servicing from accessing it
while you do it. But we are not going to support doing that, ie. if
it doesn't work don't ask us why.

>
> I see that you have the option of using it to drive the LPC2138, which
> if you used would save you the cost of crystal Y3. I was curious to know
> why you didn't use it. (reprogramming it for a higher frequency)

At the time changing from 20 MHz operation was too big of an impact on
software, and keeping a unified code base with the other products.



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