Mario  Quintero

hcs12, PLL to 25Mhz, fluctuation of power make problems to re-start  :-(

Discussion created by Mario Quintero on Jan 15, 2008
Latest reply on Jan 16, 2008 by Daniel Lundin
subjet: hcs12, PLL to 25Mhz, fluctuation of power make problems to re-start  

Hi!

I work and HCS12 DG128 with an external oscillator 5 Mhz and I configured the PLL to automatic lock at 50 Mhz, (the max high speed).

 

In normal conditions (source=5Volt ) my target start very well (25 MHz of bus speed) but my problem is in the fluctuation of the source of power

 

when fall more of 2.8 volts the CPU is dead ( is ok), and then..

when rising slowly on 3.2 volt until 5 volt  the CPU in some times don’t work ( is bad )

 

Note: To change the internal bus clock 25Mhz to 5Mhz avoid my problem but  I need work at 25 Mhz.

please, help me, and excuse my bad English.

 

 

best regards

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