CS-150 Gates and Circuits

Vocabulary flashcards covering key terms from the CS-150 lecture on gates, circuits, adders, multiplexers, memory elements, and integrated circuits.

Gate (electronics)

A device that performs a single basic logical operation on electrical signals.

Circuit (digital)

A collection of interconnected gates that performs a more complex logical task.

Boolean expression

A formula written in Boolean algebra that describes a gate or circuit’s logical behavior.

Truth table

A table listing every possible input combination and the corresponding output(s) of a gate or circuit.

Logic gate symbol

The standardized graphical icon used to depict a specific type of gate in diagrams.

NOT gate (Inverter)

A gate that outputs the opposite (complement) of its single input.

AND gate

Outputs 1 only if every one of its inputs is 1.

OR gate

Outputs 1 if at least one of its inputs is 1.

XOR gate (Exclusive OR)

Outputs 1 when an odd number of its inputs are 1; 0 otherwise.

NAND gate

Outputs 0 only when all inputs are 1; the negation of AND.

NOR gate

Outputs 1 only when all inputs are 0; the negation of OR.

Transistor

A semiconductor switch that either allows or blocks current based on an input voltage; fundamental building block of gates.

Collector

Transistor terminal through which current enters when the device is conducting.

Base

Transistor terminal that controls whether current can flow between collector and emitter.

Emitter

Transistor terminal through which current exits when the device is conducting.

Combinational circuit

Circuit whose outputs depend solely on present input values.

Sequential circuit

Circuit whose outputs depend on current inputs and on its own stored state.

Circuit equivalence

The condition in which two circuits yield identical outputs for every possible input set.

Boolean algebra

Mathematical system of rules for manipulating binary (two-valued) logical expressions.

Distributive Law

Boolean identity A(B + C) = AB + AC used to transform and simplify circuits.

Half adder

Circuit that adds two single bits, generating a sum and a carry bit.

Full adder

Circuit that adds two bits plus a carry-in, producing a sum and a carry-out.

Carry bit

Binary digit that represents overflow from adding two bits, passed to the next higher position.

8-bit adder

A chain of adders that sums two 8-bit numbers; uses 17 inputs, 9 outputs, and ~40 gates.

Multiplexer (MUX)

Circuit that selects one of many data inputs to forward to a single output, based on control lines.

Control line (MUX)

Selection input that determines which data input a multiplexer routes to its output.

S-R latch

Set-Reset sequential circuit storing one bit; outputs change when S or R is momentarily lowered.

Integrated circuit (Chip)

A piece of silicon containing many embedded gates, packaged with external pins.

CPU (Central Processing Unit)

The primary integrated circuit in a computer that performs most processing tasks.

Semiconductor

Material, such as silicon, whose conductivity lies between conductor and insulator; used to build transistors.