Very promising. Can you point us to the SA docs?
Jochen
On Tue, 09 Jul 2002 13:55:20 +0100, Andy Collins wrote:
>
>Hi Folks,
>
>I think I've come up with a different method of speeding up the MP2x00
>without needing to change the crystal.
>
>I've been pondering speeding my Newt up since discovering Stephanie's web
>page but the things that put me off were...
>1) I'd need to bring the speed down to download packages and backup (I only
>have serial coms).
>2) Running the wires around radiating at the clock frequency.
>3) It doesn't seem right to speed up everything, memory timings, LCD
>refresh rates etc.
>
>I asked a hardware savvy friend of mine if it was possible to use some kind
>of chip to switch frequency. That way this chip could be near the processor
>and the wire to the physical switch would only be handling DC. At least
>that would cross of one of my objections.
>
>The upshot of that was that it could easily be arrange but he asked the
>question why didn't I just change the multiplier? Why? because I didn't
>know there was one :-). It seems the multiplier takes the crystal frequency
>given to the StrongArm microprocessor and multiplies it by a set amount to
>give the internal frequency that the SA110 runs at. It turns out that there
>are four pins on the SA110 that set the multiplier inside the processor.
>
>The great advantage is that, if my hunch is right, only the core of the
>chip will run fast. The Voyager and therefor the serial coms etc will run
>at normal speed. The memory timing will remain unchanged. There is a
>question mark of sound (chipmunk or not) but apart from that I recon the
>Newt won't need to be switched to the normal frequency again.
>
>This is where I'm at...
>I've Downloaded the data sheets and worked out what's what.
>I've lifted the for core clock multiplier pins from the circuit board
>(_VERY_ tricky don't try this! very hard!).
>Fitted a small 4 pole tri-state DIL switch (this will be removed when it's
>all working).
>Now I can try trying the pins controlling the multiplier high or low as I
>wish. switch settings and check the results.
>
>Now here's the problem.
>
>It doesn't work!! I can change the levels on the multiplier pins but it
>doesn't seem to work properly. It either works at the same speed or hangs.
>Has anyone else looked into this? Any hints and tips from the hardware
>gurus greatly appreciated.
>
>
>Thanks.
>
>Andy.
>
>WARNING... This is proving tricky. It might turn out to be a brilliant
>idea. However, I might wreck my Newton. Don't blame me if you try this and
>wreck yours!
>
>
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>
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