USBDM  V4.12
CodeWarrior - DSC56800E

As of USBDM V4.9.3a the USBDM Target connection is created by the installer.

Selecting USBDM/DSC target connection.

Each target in a project must be set to use the USBDM_DSC target connection.

  • Create a new project or open an existing one.
  • Select the target you wish to use with USBDM and then press Alt-F7 to open the settings dialogue shown:

  • Select Debugger->Remote Debugging at the left and change the connection to USBDM_DSC.
  • Note that you will need to do the above for each Target in the project.
  • You should now be able to debug in the usual fashion.

Launch Dialogues

When starting the debugger you will be presented with the dialogue at right. After closing this dialogue debugging will proceed as usual. Some options may be disabled depending upon the hardware capabilities of the BDM interface.

Target Vdd Control - Enables supply of Target Vdd from the USBDM module
  • Enable - Enables voltage supply to target Vdd through BDM connection.

  • 3.3V or 5V - Select target supply voltage

  • Cycle target Vdd on reset - This option will cause the BDM to cycle the target power as part of the reset sequence.

  • Cycle target Vdd on connection problems - This option will cause the BDM to cycle the target power when it is having trouble connecting to the target.

  • Leave target powered on exit - The target Vdd supply will be left on when exiting the debugger.

  • Prompt to manually cycle target Vdd - Some targets may only be made to enter BDM mode through holding BKGD low while applying power. This option will cause a dialogue to appear prompting the user to remove and re-apply power to the target. The BDM will be holding BKGD low while this prompt appears. This option is not required if the BDM is supplying power to the target.

Connection Control

  • Automatically re-connect - Not currently used.

  • Connection Speed - This sets the speed of communication with the target. There is no method available for the BDM to determine the speed of the target and hence this must be specified here.
    • CFV1,2,3
      For most Coldfire targets the speed should be less than 1/5 of the target clock frequency.
      Note that the speed chosen should match the slowest clock frequency in use by the target. For example, many processors start up using the internal clock before switching to a faster external crystal and a clock multiplier. The speed should be chosen to be 1/5 of the slower internal clock frequency.
    • JTAG
      The JTAG chain on the target is (usually?) independent of the target clock. It should be possibly to communicate at the highest speed but this may be affected by cable length and quality of PCB routing. Reduce speed if it is found unreliable.
    • MC56F80xx
      This target uses the JTAG connection but currently the speed option is ignored.

Don't show this dialogue in future

  • This suppresses the display of the dialogue when connecting to the target. This is useful if you have a simple BDM without target voltage control and you find the default (or once modified) options to be adequate.
    Display of the dialogue can be restored by the following methods:
    • Try debugging without the BDM connected. An error dialogue with three options should appear. One of these options being to "Change Settings". This will open the dialogue.
    • Delete the programmer configuration file %APPDATA%%/usbdm/usbdm_HC12.cfg (or similar for other targets).
      This will restore the default settings including the dialogue display.

Popups

  • When first connecting with the target you may be prompted with a connection error dialogue if the connection can't be established. This provides you with an opportunity to return to the Connection Dialogue to change settings. This option will not be available if the connection is later lost.
  • When connecting with the target you may be prompted to cycle the target power.
    Simply turn off and turn on the target power and then press Retry to continue. The Target BKGD pin will be held low while doing this.
    This is useful for difficult HCS08 targets that may not respond to software reset when in certain modes. For example, this may occur when a blank chip has a COP timeout or some times when the processor clock is supended. Another case would be if the BKGD pin can be programmed as an general purpose I/O pin.
  • After the initial connection with the target, you may be prompted to supply power to the target.
    This means that the BDM has detected that the target has no supply.
  • The following dialogue is used to alert you to a supply overload when using the internal BDM power supply. It is likely that the target is taking more current than the BDM can supply (~100 mA but depends on the regulator used). This prompt may also appear if the target supply is momentarily shorted. The BDM detects this situation and removes the target supply until a new debugging session is started.


Using the stand-alone 56800E Flash Programmer.

It is also possible to use the 56800E Flash Programmer with USBDM but there is currently a bug that only allows a single operation each time the programmer is launched. This is caused by the programmer not correctly closing the BDM connection after each operation. This results in the BDM remaining in a busy state preventing subsequent operations. I have not been able to find a solution to this problem so far.