quartz/content/notes/02-combinatorial-logic.md

title	aliases	tags	sr-due	sr-interval	sr-ease
02-combinatorial-logic		cosc204 lecture	2022-07-19	3	250

• slides

Combinatorial Logic Circuit

[!Definition] Combinatorial Logic Circuit is a circuit whose digital outputs are dependent only on its digital inputs They can be described using logic expressions and therefore logic gates. We assume the outputs respond immediately^[1]

They can be defined:

• Using a truth table

• Using boolean equations (Q\ =\ A+\ B)

• Using graphical symbols

• [1 Bit half adder(https://i.imgur.com/mjCVU4I.png)

• 1 Bit full adder: (includes carry input)

Circuit basics:

• current flows + to -
• input to a unit (e.g., LED) is the + end

Logic Gates

• NOT
• AND
• OR
• NAND
• NOR
• XOR/EOR

[^1] : In real circuits propagation delay must be considered, hence the clock cycle on CPUs