I am currently reversw engineering a PCB and it contains a D-type register chip. The chips internal circuit diagram shows a NOT gate with two bubbles on it both in the front and the back. My question is if this is the same as a buffer or if this case some other meaning? And it would be great if a truth table could be included in the answer.
Datasheet: http://www.ti.com/lit/ds/sdls090/sdls090.pdf