Motorola DG128 User Manual

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Tips and Suggestions
Tips and Suggestions
Following are a number of tips, suggestions and answers to common questions that will solve
many problems users have with the CMD912X development system.  You can download the
latest software from the Support section of our web page at:
www.axman.com
Utilities
 If you’re trying to program memory or start the utilities, make sure all jumpers and
CONFIG SWITCH settings are correct.
 Be certain that the data cable you’re using is bi-directional and is connected securely to
both the PC and the board.  Also, make sure you are using the correct serial port.
 Make sure the correct power is supplied to the board.  You should only use a 9 volt,
300 mA adapter or power supply.  If you’re using a power strip, make sure it is turned
on.
 Make sure you load your code to an address space that actually exists.  See the
Memory Map if you’re not sure.  The CONFIG switch changes the memory map.
 If debugging under Mon12, make sure you're not over-writing RAM used by it.
 If you’re running in a multi-tasking environment (such as Windows™) close all
programs in the background to be certain no serial conflict occurs.
Code Execution
 Make sure the CONFIG SWITCH is set for the proper mode.
 CONFIG switch 3 must be ON to access the external bus (LCD display, etc) even if
executing code from Internal Flash memory.
 Under Mon12, breakpoints may not be acknowledged if you use the CALL command.
You should use one of the GO command instead.
 Check the HC12 reset vector located at FFFE - FFFF.  These 2 bytes contain the
address where execution will begin when the unit is powered on.
 When running your code stand-alone, you must initialize ALL peripherals used by the
micro, including the Stack, Serial Port, Reset and Interrupt vectors etc.
 You must either reset the COP watchdog timer in the main loop of your code or disable
it when not running under Mon12 or BDM mode.  The micro enables this by default and
if you don't handle it your code will reset every couple of ms.