3.5 Requirements for Debugging

To debug (set breakpoints, see registers, etc.) with the MPLAB ICD 4 In-Circuit Debugger system, there are critical elements that must be working correctly:

• The debugger must be connected to a computer. It must be powered by the computer via the USB cable and it must be communicating with the MPLAB X IDE software via the USB cable. Refer to the MPLAB X IDE Help file titled “Getting Started with MPLAB X IDE,” and navigate through the “Tutorial” to the “Running and Debugging Code.”
• The target device must have power and a functional, running oscillator. If for any reason the target device does not run, the MPLAB ICD 4 In-Circuit Debugger will not be able to debug it.
• The target device must have its Configuration words programmed correctly. These are set using the following: MPLAB X IDE.
  • The oscillator Configuration bits should correspond to RC, XT, etc., depending on the target design.
  • For some devices, the Watchdog Timer is enabled by default and needs to be disabled.
  • The target device must not have code protection enabled.
  • The target device must not have table read protection enabled.
  • For some devices with more than one PGC/PGD pair, the correct pair needs to be selected in the device’s configuration word settings. This only refers to debugging, since programming will work through any PGC/PGD pair.

When the conditions listed above are met, you may proceed to the following:

• Sequence of Operations Leading to Debugging
• Debugging Details