Crystal Issue in Atmel AT89S8253?

Thread Starter


Joined Jan 25, 2010
Hello friends,

I am using Atmel AT89S8253.
Currently I am using crystal 20 MHz with 27 pf ceramic capacitor, I am facing following problems

-- It dows processor speed upto 1/3. sometimes result it hang processor
-- Sometimes crystal is defected.

I am looking for option for same.

so guys do you have any suggestion???

Suggestion is highly appreciated
Thanks in advance


Joined Feb 4, 2008
You need two 27pF ceramic capacitors, from each pin of the crystal to ground. Also, some crystals, depending on their cut method, need a 25 Ohm resistor in series with one pin of the crystal and the microcontroller. You can find that information in the datasheet of the crystal.