MON51: CONNECTION TO TARGET SYSTEM LOST

Information in this article applies to:

• C51 All Versions

QUESTION

I have configured the monitor for my target hardware and have successfully downloaded my program. However, when I start running the code (either by single-step or by run) I receive the following error:

CONNECTION TO TARGET SYSTEM LOST

and I must reset the hardware. What is wrong with my configuration?

ANSWER

This error message is generated when the monitor program running on the target hardware loses communication with the monitor driver running on the PC. This is typically caused by changes (in your program) to the serial UART or to the baudrate timer. Take heed of the following:

• Make sure that you do not change the UART configuration. If you have code that initializes the UART used by the monitor, #ifdef it out.
• Do not change the timer settings for the baudrate timer.
• If you use a monitor that relocates itself into high memory leaving your program to start at 0x0000 in CODE space, make sure that you leave space for the serial port interrupt vector.

SEE ALSO

• MON51: CONFIGURING FOR TARGET
• MON51: TESTING VON NEUMANN MEMORY AREAS
• MON51: MONITOR DATA AREA
• MON51: BAUD RATES
• DSCOPE: SERIAL INTERFACE PROBLEMS WITH THE MONITOR

Last Reviewed: Tuesday, June 29, 2004