Using a resonator

[Fe2o3Fish]

A curious issue with using a resonator on the Prop-SX controller.
I'm new to the Prop-SX, SX, and the SX/B in general.

I have a 4-MHz resonator plugged into my Prop board.  I have a
simple candle program loaded into SX-Key 3.2.3 and I'm using SX/Basic.

The DEVICE & FREQ lines are:
DEVICE   SX28, OSCXT2, TURBO, STACKX, OPTIONX
FREQ   4_000_000

Now, I select menu Run->Device.   The following are checked
in the Device window:  SX28, Browout Off, Crystal-XT2, Crystal Drive,
and Crystal Feedback, Turbo Mode, and Stack + OPTION.

LOOP:
I uncheck both Crystal Drive and Feedback (Drive goes into "ghost" mode)
and press the Program button.  Everything goes OK there.

I now press the Verify button and it comes back "Device verifed OK".

Now when I press the Read button (this reads from the SX chip, right?)
and "Crystal Drive" becomes checked again so I go back to LOOP again.  :-)

Alas, the same thing happens.   I go ahead and download my program into
my Prop board and it appears to be working.  Still, moving my mouse pointer
over the Crystal Drive checkbox pops up a little box that says
"Use DEVICE XTLBUFD".  I look that up in the SX-Key manual and it doesn't
look like that's an option I want set when using a resonator.   Am I wrong here?

Where do I learn how to properly use a resonator and the appropriate
program directives and device configuration settings I need?

Thanks!

       -Rusty-

[JonnyMac]

This may be one for the Parallax guys -- I've always used OSCXT2 (XT is for crystals/ceramic resonators) and never had a lick of trouble when using resonators with built-in caps.  The SX28 documentation may provide additional information.

http://www.parallax.com/Portals/0/Downloads/docs/prod/datast/SX20AC-SX28AC-Data-v1.6.pdf

[Fe2o3Fish]

So, is there any real reason to use the Run->Devices menu item?

I'll check with the Parallax folks about the Crystal Drive checkbox.

[JonnyMac]

The only time I use that menu is to save a hex version of a program to someone else who can load it using the same menu -- this way I can protect my source code.  As an example, the company that builds our doesn't need the source code for the AP-8, DC-16, FC-4, and RC-4; they just need the code to burn into the chip so we give them a hex file.

It occurs to me, too, that you wouldn't need crystal feedback when using an external TTL oscillator is being used.  I saw that when selecting a new XT source the crystal drive was selected but disabled, this may be the normal state for XT selections.  The guy who maintains the SX-Key IDE is a good friend of mine so I'll check with him.