I can't download my program to ADUC836. Error message: “Resetting the target
The following can be used as a general troubleshooting instructions for WSD
Error message: “Resetting the target device: Failed”....
This can be caused by a number of things. Some of the more common ones:
1. The chip is not connected to the correct COM port. Verify COM1 connection or
correct software switch to other port.
2. The chip is not powered up or not in download/debug mode.
To verify download/debug mode, check that the chip spits out the reset string
from its UART when reset with the PSEN pin pulled low. You can verify this by
opening up Hyperterminal on windows (in VT-100 mode, at 9600baud, 8bits,
no-parity, 1-stop bit) and connecting to COM1 (or whatever).
3. The selected port (COM1 default) is being used by other software.
Even if the downloader says something like “Initializing Com1 at 9600
baud:.....OK!” it does not necessarily mean that it really was successful at
opening the port.
Many common applications (such as Palm HotSync manager) can run in the
background and prevent other programs from using the serial port. Disable these
programs (in the lower right of the windows taskbar) to free up the serial
port. To ensure that the serial port is free, launch hyperterminal (via the
9600COM1.ht file if possible) and see if it is able to connect. If it is, the
port is free. Be sure to close hyperterminal (or hit disconnect) before running
the downloader again.
4. The downloader and the chip are talking at two different baud rates.
If the ADuC8XX is running with an 11.0592MHz crystal (like on the eval board)
then it communicates at 9600baud with the downloader, which is the downloader’s
default baud rate. To download to chips at different crystal frequencies, a
switch must be used on the command line for the DOS downloader to indicate the
target’s clock speed. Type “/help” in place of the file name when launching the
downloader to get a list of download options.
A couple of other things to check,
Is ALE toggling?, If not then it means the part is not running. If this is the
case make sure that the Vdd level is above the POR level (approx 2.6V) if you
are using a battery the supply may drop below this causing the POR to kick in
holding the part in RESET.
Check that the crystal is oscillating, if the crystal is not oscillating (or
takes too long on powerup to start oscillating) then the PLL may not lock, this
will result in a core frequency of +/- 20%. As a result of this the baudrate
will not be accurate and the download will fail.
On page 7 of uC004 the security bits are explained. There is a mode called
SERIAL SAFE mode, which prevents of entering in serial download mode, even if
you have PSEN grounded via a 1K resistor while RESET is asserted. Although only
the ADuC816 and the ADuC824 are mentioned, this also applies to the ADuC834 and
ADuC836. Could you check that this mode is not enabled?