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µVISION DEBUGGER: Strange Data received sharing the Serial Port

Information in this article applies to:

  • µVision Version 2.05


I've successfully configured the monitor for my target hardware and have my target program running. However, I'm having trouble getting the correct data from the target's serial port. 

I am typing characters in the serial window. My target program reads these and stores them in a queue. When I look at the queue, I have many extraneous characters mixed in with the characters I typed. 

Is the monitor interfering with the serial port? If so, how do I correct it?


The debugger communicates with the target monitor using the serial port. This is how your programs get downloaded, and single-steps are performed. However, monitor communication uses a protocol that avoids interfering with your code. So you should be able to share the serial port with the debugger.

To see if the monitor is the culprit, follow these steps:

  1. Load the monitor.
  2. Run your program.
  3. Enter all your data in the serial window.
  4. Wait for the data to get processed by your target hardware.
  5. Stop program execution and look at the data buffer.

There should be no problems with the data (assuming the problem was caused by the monitor).

If you still see strange characters, there must be a problem with your program.


Last Reviewed: Monday, January 25, 2021

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