ARM Technical Support Knowledge Articles

MON51.DLL FOR C51 V6.00

Applies to: uVision Debugger


Information in this article applies to:


When I try to configure the monitor settings for the uVision Version 2 debugger, I receive the following message:

Error: Can't load driver 'c:keilc51monitormon51.dll'

Then, when I start the uVision debugger, I receive the following error messages.

*** Error: 'c:keilc51in	p51.dll' not found
*** Error: 'c:keilc51monitormon51.dll' not found

What's going on?


The uVision Version 2 debugger is currently not fully completed. It lacks support for the Monitor-51 and several devices. We are working diligently to add support for the monitor and for many more devices. When they are completed, they will be made available on the web at


As intermediate solution you should use the dScope-51 debugger that is available in the C51 Version 5 package. You may invoke dScope-51 via the uVision2 tools menu.

The following steps show how to add dScope51 to the Tools menu in uVision.

  1. From the Tools menu select the Customize Tool Menu item. The Customize Tools Menu dialog appears.
  2. Add a new menu item and enter the following information:
    • Menu Content: Run dScope-51 with @P
    • Command: C:C51BINDSW51.EXE (the path depends on your installation)
    • Initial Folder: <empty>
    • Arguments: -i @P.INI

Now, you may start the dScope-51 debugger directly from the uVision Tools menu. uVision passes an INI file (having the same name as your project) to dScope.

You may create the INI file using the uVision editor. For example:

---- Example:  HELLO.INI (dScope INI file for HELLO project)
LOAD 8051.DLL      // the device you want to simulate with dScope-51.
LOAD HELLO         // the application you want to load
g, main            // run program til entry 'main'


Additional information is included in the RELEASE.TXT file included with UV2 and C51 V6.00.


Article last edited on: 2005-07-09 11:20:03

Rate this article

Disagree? Move your mouse over the bar and click

Did you find this article helpful? Yes No

How can we improve this article?

Link to this article
Copyright © 2011 ARM Limited. All rights reserved. External (Open), Non-Confidential