MPLAB ICD 4 Help

How to Invoke the Bootload Mode

If the MPLAB X IDE or MPLAB IPE cannot communicate with the debugger, the debugger may need to be forced into bootload mode (download new firmware). Some possible reasons could be the following:

•	If steps 1-5 in “General” did not correct the debugger issue.

•	If the MPLAB X IDE or MPLAB IPE cannot communicate with the debugger (as one example, LEDs continually alternate between purple and blue).

•

If the MPLAB X IDE Output window shows an asterisk (*) next to the Application version number, the debugger’s firmware is not the newest. This can occur if the Project Properties Firmware option has the “Use Latest Firmware” box unchecked and there is a new firmware version available with the MPLAB X IDE version. In this case, check the “Use Latest Firmware” box and click the Refresh Debug Tool Status icon in the MPLAB X IDE dashboard display. If there is still an asterisk next to the Application version number, or the debugger issue is not resolved, proceed to the following steps for bootload mode.

Refer to “Indicator Lights (LEDs)” for more information on LED modes and bootloader errors.

Perform the following steps to force the debugger into bootload mode:

1.	Disconnect the Mini-B USB cable from the debugger.

2.	Perform one of the following two methods to create a short:

Preferred Method: If you have the recommended Microchip 9V power supply (AC002014), plug it into the MPLAB ICD 4, but unplug the power cord from the wall or power strip.

OR

Alternative Method: If the recommended power supply is not being used, make sure no power is connected to the debugger. Then, insert a small metal screwdriver into the 9V female barrel connector so that it contacts the center pin and the metal tang at the bottom of the jack.

Figure: Alternative Method of Creating a Short

3.	Plug the Mini-B USB cable back into the debugger.

4.

As soon as both LEDs flash quickly, immediately unplug the power cable from the debugger or remove the screwdriver (within 1 second). If the LEDs are steady on purple, proceed to the next step. If the LEDs are blue, you did not perform the action fast enough and must repeat the process starting at step 1).

5.	Try to reestablish communication with the MPLAB X IDE or MPLAB IPE. If successful, the latest firmware is automatically downloaded and the debugger goes through a built-in self-test. When complete, the LEDs are steady on blue and the debugger is ready for operation.

Microchip Support Help Updated: 2019-06-25 10:29:53Z Help Page: 33