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SX and resonators — Parallax Forums

SX and resonators

Fe2o3FishFe2o3Fish Posts: 170
edited 2007-11-20 00:12 in General Discussion
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-SX 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. smile.gif

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!

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-Rusty-
--
Rusty Haddock = AE5AE = rusty@fe2o3.lonestar.org
**Out yonder in the Van Alstyne (TX) Metropolitan Area**
Microsoft is to software what McDonalds is to gourmet cooking

Comments

  • BeanBean Posts: 8,129
    edited 2007-11-19 01:48
    Rusty,
    The device window is basically READ-ONLY. Any changes you make there don't affect anything. You need to change the settings on the DEVICE line.

    Bean.

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    www.iElectronicDesigns.com

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  • Fe2o3FishFe2o3Fish Posts: 170
    edited 2007-11-19 04:17
    Hmmm.... If the Device window is read-only then I s'pose someone should change the SX Key
    Manual to say that because it states "You may modify these settings manually and program or
    reprogram the chip, however, those modifications will not be reflected in the source code."

    The manual reads like the object file would be modified prior to loading into the SX chip.

    Maybe I'm reading things wrong?

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    -Rusty-
    --
    Rusty Haddock = AE5AE = rusty@fe2o3.lonestar.org
    **Out yonder in the Van Alstyne (TX) Metropolitan Area**
    Microsoft is to software what McDonalds is to gourmet cooking
  • PJMontyPJMonty Posts: 983
    edited 2007-11-19 19:02
    Rusty,

    No, the device dialog isn't read only. You can make changes there, program the chip, then read it back and the checkboxes, etc won't change. You can also verify the chip and they will be the same. In fact, I just went and did it as a test to prove it works. You can do it yourself. Program a chip, read it into the device dialog, change the "Add/Sub with C", program the chip again, and then read it again. You'll see the check box has not changed.

    However, you can manually make changes to the device window that aren't legal for a given chip. For example, you could set the chip type to SX18 and then program an SX-28. When you read it back, the checkbox won't stay on SX-18 because you haven't transformed the chip from one device to another simply by programming it.

    I suspect you are attempting to set options for the SX-28 that don't actually exist for that chip. While you can change options via the device dialog, you don't want to. Why? Well, for just the reason I suggested above. If you want to change an option on the chip, change your code, re-assemble and re-program. That's the entire reason for the DEVICE directives. They let you store the way you want to set up your chip in your source code, not in your brain. This way, when you come back to the project in the future and make changes, you won't have to remember that after programming, you have to manually go to the device dialog, change some settings, and program it again.

    Thanks,
    PeterM
  • Fe2o3FishFe2o3Fish Posts: 170
    edited 2007-11-19 22:22
    Well, Bean was the one that said the Device windows was read-only. smile.gif

    I understand the illegal options for a given chip although, so far, I've but
    only one chip available and that's the SX-28 on the Prop-SX board.

    Good design practices suggest that the options NOT available for the chip
    selected (even in the same window!) should be grayed out.

    Any hoot, I'm starting to see how this window is used but the advice and the
    documentation don't seem to match it completely. In my opinion, the
    documentation may need some more work.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    -Rusty-
    --
    Rusty Haddock = AE5AE = rusty@fe2o3.lonestar.org
    **Out yonder in the Van Alstyne (TX) Metropolitan Area**
    Microsoft is to software what McDonalds is to gourmet cooking
  • PJMontyPJMonty Posts: 983
    edited 2007-11-20 00:12
    Rusty,

    You may be correct regarding the docs. Regardless, my recommendation is to ignore the device dialog as a general rule.

    Regarding updating the dialog, you're also correct. However, it's pretty low priority since most people don't have a need to use the device dialog.

    Just curious, what was your reason for using the device dialog?

    Thanks,
    PeterM
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