Digital Design 1 Exam 1

Analog deals with _______________ values.

continuous

Digital deals with __________ values.

discrete

The only two valid values for a single binary digit are ___ and ___.

1 and 0

Serial means processing bits __________________.

one at a time

Parallel means processing bits _________________________.

many at a time

For a 2-input AND function, what produces a 1?

both inputs are 1 (HIGH)

For a 2-input OR function, what produces a 0?

both inputs are 0 (LOW)

The "leading edge" is always the "rising edge".

False

Rise time is defined as ___________.

the amount of time it takes a pulse to go from LOW to HIGH

Fall time is defined as ___________.

the amount of time it takes a pulse to go from HIGH to LOW

Amplitude is defined as ___________.

the height from baseline of the signal to the max value

Pulse width is defined as ___________.

a measure of the width of the pulse

The HIGH and LOW logic levels of incoming voltage also include a voltage range which is unacceptable as either value.

True

A periodic waveform is one that repeats itself at a fixed interval.

True

A nonperiodic waveform is commonly used as a clock signal.

False

Each binary digit increases in value by powers of ____.

2

Each hexadecimal digit increases by powers of ____.

16

Each octal digit increases in value by powers of ____.

8

Hexadecimal digits start at 0 and go to H.

False

The letter 'C' in hexadecimal stands for the decimal value ____.

12

When subtracting in binary, first convert to 2's complement, then __________.

add

The binary value 1101 has the same value whether it designates a signed number or an unsigned number.

False

The binary value 0011 has the same value whether it designates a signed number or an unsigned number.

True

A signed number in signed-magnitude form ____________________.

flips only the first bit to convert to a negative number.

A signed number in 2's complement form ____________________.

flips all bits and adds one to convert to a negative number

The NAND gate is functionally equivalent to the ____________ gate.

Negative-OR

The NOR gate is functionally equivalent to the __________ gate.

Negative-AND

To get the output of a NAND gate, first AND (Boolean multiply) the inputs, then invert the result.

True

To get the output of a NOR gate, first invert the inputs, then OR (Boolean add) the inverted inputs.

False

All gates require at least two inputs except the _______ gate.

NOT

DC Supply Voltage

maximum voltage a gate or IC can handle: either 1.8V, 2.5V, 3.3V, or 5V

Fan-Out

the maximum number of inputs that can be connected to a gate's output to maintain output voltage within specified limits.

Propogation Delay Time

how long it takes for an input of a gate to change its output

Input and Output Logic Levels

specifies input voltage ranges for HIGH, LOW, and undeterminable outputs.

OR (Equation)

NAND (Equation)

AND (Equation)

NOT (Equation)

NOR (Equation)

XNOR (Gate)

AND (Gate)

XOR (Gate)

NOT (Gate)

NAND (Gate)

OR (Gate)

NOR (Gate)

Boolean Addition is represented by the OR Gate

True

Boolean Multiplication is represented by the OR Gate.

False

74xx11

Triple 3-input AND chip

Triple 3-input NAND chip

74xx10

Quad 2-input AND chip

74xx08

NOT/Inverter chip

74xx04

Quad 2-input NAND chip

74xx00

Quad 2-input OR chip

74xx32

Associative

A(BC) = (AB)C

A + (B + C) = (A + B) + C

Commutative

AB = BA

A+B = B+A

Distributive

A(B + C) = AB + AC

This expression is in SOP (Sum-Of-Products) Form (non-standard): AB + BC + AC

True

The following expression is in STANDARD POS (Product-of-Sums) form: (A+B)(B+C+D)(C+D)

False

An SOP expression is equal to 1 if at least one TERM is equal to 1.

True

A POS expression is equal to 0 if at least one of its terms is equal to 0.

True

In a standard SOP expression, and in a standard POS expression, every term must contain every variable in the domain of the expression.

True

What is the expression derived from this truth table?

A'BC + AB'C'

Which expression matches the logic gates?

What is a variable?

inputs and outputs

What is a literal?

variable value or negative

What is a term?

group of one or more variables

What is a domain?

list of all possible variables

What is an expression?

group of terms

An example of sum of terms:

(A + B)

An example of product term:

CD

SOP stands for?

sum of products

POS stands for?

product of sums

Standard SOP:

AB + AC + BC

(AB)(C+C̅) + (AC)(B+B̅) + (BC)(A+A̅)

ABC + ABC̅ + ABC + AB̅C + ABC + A̅BC

ABC + ABC̅ + AB̅C + A̅BC

Standard POS:

(A+B)(B+C)(A+C)

(A+B +CC̅)(B + C + AA̅) (A+C+BB̅)

(A+B+C)(A+B+C̅)(A+B+C) + (B+C+A̅)(A+B+C) + (A+C+B̅)

(A+B+C)(A+B+C̅)(A̅+B+C)(A+B̅+C)

What makes a 1 in a POS truth table?

if not represented

What makes a 1 in a SOP truth table?

if represented