I2C bus VS crystal used for Propeller

jtilghman

Just wondering if you are using a 6.25 Mhz crystal instead the standard 5 Mhz, can/will this change how using I2C works and it's timing ?

If so, what changes need to be made in the code for it work correctly ?

I ask, because what I find is everyone sets xtal = 5.00.00

Most likely a very easy question to answer, but I would like to make sure I know where to look since I am having problems getting my I2C devices working.

Thanks,
JT

msrobots

depends.

When you set _clkmode and _xinfreq at the beginning of your main program then a third constant _clkfreq is automatically calculated.

Well written driver use this constant to adjust for differences in clock freq. But not all do.

But Ic2 is not really timing sensitive, so the difference between 80 and 96Mhz should not matter much.

Enjoy!

Mike