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Sx28 debug not working — Parallax Forums

Sx28 debug not working

q-bertq-bert Posts: 3
edited 2011-05-09 13:10 in General Discussion
Hi!

I've been trying to get my de-bugger working for a while now. The sx usb key rev b programs the chip fine, but when i'm running debug the step/run/jog functions are all grayed out. I tried running a "debug_test" program I found on this forum, still no help. The external resonator is not conencted to the chip, and i'm using an external DC power supply with 10 volts into a 5volt regulator.
I have tried it on my Vista laptop at home, and an XP at uni.

Any clue about what's going on?

Thanks,
Q-bert

Comments

  • PJMontyPJMonty Posts: 983
    edited 2011-05-06 16:57
    Q-Bert,

    How are you getting into the debugger? A common mistake is to use Run->Program (or CTRL-P) to program the chip and then using Run->Debug(reenter) (or CTRL-ALT-D) to go into debugging mode. This won't work.

    You have to program the chip using Run->Debug which will program the chip with an extra bit of code that the SX-Key uses to talk to the chip for debugging. Without this code, the debugger will run, but it can't talk to the chip and the various buttons will be grayed out.

    Thanks,
    PeterM
  • q-bertq-bert Posts: 3
    edited 2011-05-08 22:20
    Thank you for your reply, PJMonty!

    Yes, I'm using Run->Debug and it's still grayed out. I'm thinking either there is something wrong with my breadboard setup ( messy and noisy wires ) or there is something wrong with the SX key.
    Here is a pictuer of it http://img34.imageshack.us/i/cimg4006.jpg

    I've tryed cleaning up the wires since the photo was taken, but no change. Any ide what it could be?
  • PublisonPublison Posts: 12,366
    edited 2011-05-09 11:14
    Is your Oscillator in circuit when debugging? It needs to be out of the circuit when using the SX-Key in debugging mode. The SX-Key sets the clock.
  • PJMontyPJMonty Posts: 983
    edited 2011-05-09 12:03
    You say the external resonator isn't connected, but I am curious what that metal encased chip is. It looks a lot like a TTL clock chip, but it's hard to tell what connections are going where on the SX-28. A TTL chip that is in circuit will cause all sorts of unanticipated mayhem with programming and debugging. You can't just disable the TTL clock, you have to physically remove the clock connection from the SX chip.

    It's always tricky when you're having problems with a custom circuit, especially one on a breadboard. Do you have a Parallax board that you can test on to make sure the chip and SX-Key are working properly? Without that, it's hard to know exactly where the problem is.

    The other problem is that the USB version of the SX-Key has always been more fussy about going into debug mode properly than the older serial key. Are you running the latest version of the SX-Key IDE and the FTDI driver USB driver?

    Thanks,
    PeterM
  • ZootZoot Posts: 2,227
    edited 2011-05-09 13:10
    Check for dirty connections between your Key and your test circuit. Use short wires. I've found even w/the serial Key that noisy connections will prevent a good debug connection to the PC, even when the chip programs and operates properly. This is often evidenced by "grayed out" or non-functioning step, start buttons in the SX IDE. All this presumes you have pulled the clock source from the circuit and properly set the device clock (used by the Key to generate a clock for the chip during debug).
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