Tools and devices should be connected directly to a USB port on
your debugging PC. If this is not an option, you may reduce/eliminate problems by:
- Disconnect any other USB devices
connected to the hub
- Switch ports on the USB hub
- Set the tool clock frequency low.
E.g., Set JTAG Clock < 600 kHz.
- If Use external reset is an
option for your tool/device combination, enable this
Note: The AVR Dragon should be connected
through a powered USB hub. This because the power supply on the Dragon can be too weak if
the motherboard does not provide enough power. If the Dragon times out or freezes, then the
hub might be of too low quality.