JAJSF42B April 2018 – June 2019 DLPC3478
To avoid potentially damaging current caused by floating CMOS input-only pins, TI recommends that unused ASIC input pins be tied through a pullup resistor to its associated power supply or a pulldown to ground. For ASIC inputs with an internal pullup or pulldown resistors, it is unnecessary to add an external pullup or pulldown unless specifically recommended. Internal pullup and pulldown resistors are weak. Do not expect them to drive the external line. The DLPC3478 device implements very few internal resistors and these are noted in the pin list. When external pullup or pulldown resistors are needed for pins that have built-in weak pullups or pulldowns, use the value 8 kΩ (max).
Never tie unused output-only pins directly to power or ground. Instead leave them open.
When possible, TI recommends that unused bidirectional I/O pins be configured to their output state such that the pin can be left open. If this control is not available and the pins may become an input, then they are typically pulled-up (or pulled-down) using an appropriate, dedicated resistor.