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

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. 


--- mworksjjf <[email protected]> wrote:
> 
> Hi,
> 
> Thanks for the tip, but I found that the application
> that runs 
> correctly exhibited more of a voltage range than the
> failing 
> application:
> 
> Good application - 3.17V - 3.30V
> Bad application  - 3.19V - 3.31V
> 
> Even so, lets say this was the problem, any ideas on
> how I would fix 
> it?   Is there a possible solution I can try and see
> if the problem 
> goes away?
> 
> Any other ideas on this?
> 
> Thanks!
> 
> Jon.
>  
>
> 


		
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