The TPI interface found on some Atmel tinyAVR devices, is similar to the PDI interface, with the addition of the RESET pin.
As the TPI interface uses the RESET pin, the RESET pin can not be disabled by setting the reset disable fuse. This will will prevent furter programming of the device using the Atmel AVRISP mkII. The only option is to use a programmer with the capability of driving 12V to the reset line (i.e Atmel STK600).
The TPI interface uses internal pull-ups on the data line. Avoid any pull-downs on the TPI data line.