An NC (no connect) pin indicates a device pin to which no internal connection is present or allowed. Micron recommends that no external connection be made to this pin. However, if a connection is inadvertently made, it will not affect device operation. Sometimes NC pins could be reserved for future use. Refer to the part’s data sheet to confirm whether the pin is reserved for future use.
An NF (no function) pin indicates a device pin that is electrically connected to the device but for which the signal has no function in the device operation. Micron strongly recommends that no external connection be made to this pin.
A DNU (do not use) pin indicates a device pin to which there may or may not be an internal connection but to which no external connections are allowed. Micron requires that no external connection be made to this pin. Refer to the part’s data sheet for more details.