I presume that by if-then-else you mean ((a and b) or ((not a) and c)), so the output is either b or c depending on the state of A.
So if you want to do it as TTL gates, that's two ands, an or, and an inverter.
Of course you can apply boolean-logic equivalencies to express the same thing other ways.
Or you can go looking for a chip which directly implements that input-selection logic. They do exist, though they tend to be used where you're switching two complete busses or where there are more than two inputs and the selection input is more than one bit wide.
Discussions
Best Answer 10 years ago
Try researching a device called a multiplexer, that should tell you much.
--Purduecer
10 years ago
What specifically are you trying to do?
Answer 10 years ago
binary calculator out of an iphone box, i have rest of logic worked out. uses LEDs and 7 buttons (1,0,x,+,-,/).
10 years ago
AND gate followed by an inverter (octal, nand, whatever). Trivial boolean logic.
10 years ago
I presume that by if-then-else you mean ((a and b) or ((not a) and c)), so the output is either b or c depending on the state of A. So if you want to do it as TTL gates, that's two ands, an or, and an inverter. Of course you can apply boolean-logic equivalencies to express the same thing other ways. Or you can go looking for a chip which directly implements that input-selection logic. They do exist, though they tend to be used where you're switching two complete busses or where there are more than two inputs and the selection input is more than one bit wide.