ARM: µVISION DEBUGGER: UNEXPECTED DEBUGGER EXIT

Information in this knowledgebase article applies to:

• µVision Version 3.20 and later

SYMPTOM

When debugging a Luminary Micro LM3S6965 device and using the PLL to control the clock, clicking the Run button after clicking the Reset button causes the Debugger to exit back to µVision.

CAUSE

The Cortex-M3 core is being reset but the on-chip peripherals (specifically, the PLL) are not. The debugger's Reset Option (Options for Target — Debug tab — Settings button — Debug — Connect & Reset Options) controls how a Reset is performed. When you select Autodetect, the debugger reads the Hardware ID register from the device to determine the best way for the debugger to issue a Reset for that device. For some Luminary Micro devices, however, the Hardware ID can't be used to identify the best way to reset the device.

RESOLUTION

If you are enabling the PLL and your Luminary Micro device displays this symptom, change the Reset Option setting from Autodetect to SYSRESETREQ. With this selection both the Cortex-M3 core and the on-chip peripherals will be reset.

MORE INFORMATION

• µVision DEBUGGER: PROTECTION FAULT USING LUMINARY DLL

SEE ALSO

• Refer to Debug in the ULINK2 User's Guide.

Last Reviewed: Tuesday, June 24, 2008