Chapter Four - Gates and Circuits

Question 1

NOT gate?

Answer 1

• INVERTS its single input value (0 becomes 1, 1 becomes 0)

- X(output signal) = A’

Question 2

AND gate?

Answer 2

• 1 if both input values are 1, otherwise 0

- X = A (dot) B

Question 3

OR gate?

Answer 3

• 0, if 0 0, otherwise 1

- X = A + B

Question 4

XOR gate?

Answer 4

• 00, 11 produce 0; 01, or 10 produce 1

- X = A (+ and circle around it) B

Question 5

NAND and NOR gate?

Answer 5

• opposite results of AND and OR
  NAND > X = (A dot B)’
  NOR > X = (A+B)’

Question 6

gate?

Answer 6

• device that performs basic OPERATION on ELECTRIC SIGNALS, accepting 1+ signals and producing SINGLE signal.

Question 7

circuit?

Answer 7

• combination of GATES designed to complete specific function

Question 8

logic diagram?

Answer 8

• GRAPHICAL REPRESENTATION of CIRCUIT (each type of GATE has own SYMBOL)

Question 9

truth table?

Answer 9

• table showing all POSSIBLE INPUT VALUES & assiociated OUTPUT VALUES

Question 10

transistor?

Answer 10

• device that acts as a WIRE/RESISTER, depending on VOLTAGE level of INPUT signal;

Question 11

semi-conductor?

Answer 11

• neither good conductor(copper) nor good insulator(rubber);&raquo_space; silicon

Question 12

combinational circuit?

Answer 12

• circuit whose output is SOLELY determined by INPUT values;

Question 13

sequential circuit?

Answer 13

• output is a function of INPUT values and CURRENT STATE of circuit;

Question 14

circuit equivalence

Answer 14

• BOTH circuits produce same OUTPUT for input value combinations (distributive law)

Question 15

adder

Answer 15

• circuit that performs ADDITION on binary

Question 16

half adder

Answer 16

• circuit that finds the CARRY bit

Question 17

full adder

Answer 17

• takes into account an INPUT CARRY bit;&raquo_space; two half adders

Question 18

multiplexer

Answer 18

• circuit that uses a few INPUT CONTROL SIGNALS to determine WHICH of several INPUT DATA LINES is routed to its OUTPUT; (transfers information from one place to another; e.g. memory to cpu)

Question 19

integrated circuit?

Answer 19

• Piece of SILICON on which multiple GATES have been EMBEDDED