Re: Strange ICTRL related behaviour on Axiom CME555@40MHz

Hi Alex,

Thanks for your help - the problem was solved by adding 2 wait states 
for the external ram.

Best regards,

Jon.

--- In [email protected], alex shulman <alex_shulm@y...> wrote:
> Jon,
> 
> Make sure you're mesuaring the voltage on the chip and
> not at a test point, which is usually close to power
> regulator. 
> 
> Voltage drop on the PCB wiring can make the
> difference.
> Also try see the rail with scope to make sure the
> power does not have excessive noise, spikes. 
> 
> Check also that the power regulator has current limit
> high enough.
> 
> Try tp add tantalum cap ~10-100uF across 3.3V supply.
> 
> Another solution - run it directly from internal
> flash.
> External RAM may draw to much current. 
> 
> Also try to add a wait state for the ext RAM CS.
> 
> Lower the frequency gradually, to find working one.
> (You may be able to run it at 36MHz, for example.)
> 
> Alex. 





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