Timing issue

Toley

Hello everyone,

I'm new with the propeller but I have many years of experience with others microcontrollers and I'm an electronic specialist.

The propeller is simply a bomb! I've buy a Demo board with some other spare props and look at many available demo (TV, VGA, SD card, etc...) and I'm really impressed. For now I try to learn spin language.

Here are my first remarks

First : This forum is really hard to follow and search cause every topic are in the same section. But I will soon know if answers to questions come fast

Secondly : Is there plan to add a icon toolbar to the propeller tool software ? I think it can be usefull.

At last here is my question : I get different timing with different xtal setting. It's probably a known issue but I didn't found anything on it.

This setting with a 5MHz xtal
_xinfreq = 5_000_000
_clkmode = xtal1 + pll16x

don't give the same timing result as this one with a 20MHz xtal
_xinfreq = 20_000_000
_clkmode = xtal2 + pll4x

thanks for any answers

Rayman

You can't use the PLL with fast crystals... I think the limit is 8MHz or something...

bambino

_xinfreq = 5_000_000 is telling the IDE which crystal you are using, in this case the demo board, it should be set to _xinfreq = 5_000_000. Unless you have physically removed the crystal and placed in another value. The Propeller Manuel covers this and how to use the built in RC oscillator. It is the place to start. Propeller Wiki and Good thread index are also available to help you narrow your search.
Welcome to the Propeller!

Toley

Thank you for the answers. I think you're right Rayman, can't use PLL with high frequency crystal. The best thing I can do is stay with a 5MHz crystal and PLL16X.