Hi Brad/Tom,
I just wanted to follow up and say thanks for your responses.
We don't want to disconnect the ATN line... so we're going to stick
with adding a watchdog timer to reset the chip when/if it hangs. I am trying to
look at this as a blessing in disguise because the watchdog code is probably
handy to have. (who knows what other scenarios reset the chip)
You might also be interested to know that BX24p resets the chip on our
breadboard after unplugging the USB cable (instead of just when it was plugged
in after a reset with my BX24/dev station setup). Interesting to note.
-Trevor
--- In b..., "Brad Watts" wrote:
>
> The same thing can happen just by restarting Windows on XP machines. It
> sounds like the ATN line is toggling when the USB dongle is connected. You
> may need to disconnect the ATN line between the serial cable and the
> processor to prevent this from happening
>
>
>
> Here is the info from the manual:
>
>
>
> Serial Port Connector
>
> Once you've downloaded a program to the BX-24 chip, the development
board's
> DB-9 serial connector
>
> may then be used for other purposes. If you do use the connector for
> anything other than downloading
>
> your program, you should remove Jumper 1 from the option header. By
removing
> Jumper 1 you
>
> disconnect the BX-24's ATN line (pin 3) from the serial connector and
avoid
> accidentally putting the BX-
>
> 24 in download mode.
>
> Listed below are the connections needed to add a DB-9 serial downloading
> connector to your own BX-24
>
> project.
>
> DB-9
>
> Connector BX-24 Chip
>
> Pin 2 = TX >--------< Pin 1 of the BX-24
>
> Pin 3 = RX >--------< Pin 2 of the BX-24
>
> Pin 4 = ATN >--------< Pin 3 of the BX-24
>
> Pin 5 = Ground >--------< Pins 4 or 23 of the BX-24
>
>
>
> Brad
>
>
>