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 CME-12B/BC development system. You can download
the latest software from the Support section of our web page at:
If you're trying to program memory or start the HC12 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
Make sure you load your code to an address space that actually exists. See the
Memory Map if you're not sure.
Make sure you're not over-writing memory used by the monitor program.
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.
Make sure the CONFIG SWITCH is set for the proper mode. If executing from the
BDM, you should turn switches 1-4 OFF. If debugging from internal flash EEPROM,
disable any reset macro's.
If you're using D-Bug12 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 FFFEh - FFFFh. 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, etc.
You must either reset the COP watchdog timer in the main loop of your code or disable
it when not running under MBug or BDM mode. The micro enables this by default and
if you don't handle it your code will reset every couple of ms.
Your make or build should create a .MAP file. Some versions change this to a .MP
file. At the top of this file should be a label __START. This is where you should
CALL or GO to when debugging in D-Bug12.