If I see a two input OR with bubbles on both inputs and the output, I
automatically (i.e. without a lot of conscious thought) say, "That's
Sure, it dfoens;t take much thought. but it does jolt me for a couple of
milliseconds. I find I follow things more easily if I do the DeMorganing
in my head.
a negative-logic OR that's masquerading as a
positive-logic AND gate.
It's pretty much automatic, like resistor color code--you don't
mentally run the color chart or some inande mnemonic aid in your
head, you just grab a 47K resistor out of the pile because it looks
like a 47K resistor.
Sure... (Although I do have to think a little for some of the E96 series
still)
So give me the DeMorganed representation any day.
I'll have more
confidence that the designer has his thought processes straight.
On the other hand, conventional logic symbols are weak in that they
shows the component units, but doesn't necessarily show what they're
supposed to do. For example, it may be expeditious to construct a
XOR gate from leftover NAND gates and inverters, but there's no good
way to show the intended function and still keep the components
identified.
Well, tyou vcan label that as a block on the scheamtic, I guess.
Incidentally, I always liked the way that DEC drew a NAND gate symbol
rounf the juntionons on a wired-AND of open-colllector gates.
-tony