[time-nuts] Why these Crystal Frequencies?
bell.peter at gmail.com
Wed Dec 14 23:17:03 EST 2011
11.0592MHz is another crystal used for accurate baud rates -
especially on MCUs that had a 12MHz maximum clock (like the Intel
So is 9.8304MHz - used on a number of Mototola (now Freescale) MCUs
17.734475 is 4 times the PAL color burst frequency of 4.433619MHz
I'll see if I can think of anything else.
On Thu, Dec 15, 2011 at 11:54 AM, Brooke Clarke <brooke at pacific.net> wrote:
> Hi Rex:
> Thanks, I had 14.7456 mis listed (off one row) as the 4X CB freq. I've
> updated the table.
> Have Fun,
> Brooke Clarke
> Rex wrote:
>> 14.31818 is 4x the analog color burst (~3.58)
>> 18.432 divides cleanly for baud rates. I've used it as a PIC clock for
>> that. I think some of the others may be too, but I didn't recognize or do
>> the math to see.
>> On 12/14/2011 7:13 PM, Brooke Clarke wrote:
>>> Hi Pete:
>>> Maybe you can shed some light on the common xtal frequencies table where
>>> there's no explanation given?
>>> An answer is not it's an "even" frequency or "it's an even binary
>>> frequency. That's true for most of these and the factors are part of the
>>> table above.
>>> The question is why do they exist?
>>> such as:
>>> 32.0 kHz
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> and follow the instructions there.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> and follow the instructions there.
More information about the time-nuts