ATtiny44A clock out is 4MHz?

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I'm enabling the CKOUT fuse and can see a 4MHz square wave generated on the clock output pin. I thought this should be 8MHz? I believe that is the freq. of the internal oscillator. Vsupply is 3.3V.

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 If the System Clock Prescaler is used, it is the divided system clock that is output.

 

You haven't set the prescaler, have you (if not, you should see 8 Mhz if the divider is off)? From the factory, the CKDIV divider is ON, giving 1 MHz

 

Are you misinterpreting your viewing of the pin?

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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That's strange... I only loaded code to the MCU and cleared the CLKDIV fuse as well. The scope reads 4MHz and the signal also looks very good, so unless the scope is drunk the signal is 4MHz :)

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Did you accidentally write to the prescaler?  I believe it requires a certain seqeunce, to prevent accidental changes. 

Otherwise, take a good look at the scope, make sure you are not on some expanded view, where the scope timebase is changed.  

If it is 4MHz, you see a rising edge every 0.25us  (250ns).

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

Last Edited: Wed. May 8, 2019 - 08:17 AM
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It would be helpful if you showed us your code and fuse settings!

 

Jim

 

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And a picture of the scope trace.