CMOS inputs: “whatever may make the PCB layout easiest (annotate to SCH), or makes using the input later (with a wire?) easier.\ — Bruce Walter
“For example, if I am routing traces for a 74HC14 hex inverter, and I don’t use 5 of the inverters, I tie the inputs of the unused gates on the pin 1 side of the chip to GND, and the inputs of unused gates on the pin 14 side of the chip to VCC. The way I route my power buses, the GND track is under the pin 1 side of the chip, and the VCC is under the pin 14 side of the chip. Electrically, there is no reason I know of to choose VCC over GND for CMOS inputs. … This is what I do for double-sided boards. Of course, this advice is moot for boards with VCC and GND planes, since VCC and GND are equally accessible.” — Ivan Baggett http://www.bagotronix.com “Actually, I have sometimes daisy chained unused sections of a HC14 or HC04 since the pins in question are adjacent and the lengths of the nets are minimized. The first in the chain connects to the nearest of Vcc and GND. If I recall correctly, TTL gates required a series resistor (I don’t know why), LSTTL did not but both had to be pu
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