9.1 USB Port Communication
The MPLAB ICD 4 In-Circuit Debugger is connected to the host computer via a USB port, version 2.0 compliant. The USB connector is located on the side of the debugger.
The system is capable of reloading the firmware via the USB interface.
Power for the debugger can be derived from the USB interface, however, the USB connection is primarily for communications between the computer and the debugger. It cannot be used to power the target. An external power supply is required. The debugger is classified as a high-power system per the USB specification and requires 300 mA of power from the USB to function in all operational modes (debugger/programmer).
Cable Length – The computer-to-debugger cable, shipped with the debugger kit, is the correct length for proper operation.
Powered Hubs – If you are going to use a USB hub, make sure it is self-powered. Also, USB ports on computer keyboards do not have enough power for the debugger to operate.
Computer Hibernate/Power-Down Modes – Disable the Hibernate or other power saver modes on your computer to ensure proper USB communication with the debugger.