Complete Test Bank Digital Logic Ch.12

Chapter 12: digital logic

TRUE OR FALSE

T F 1. The operation of the digital computer is based on the storage and

processing of binary data.

T F 2. Claude Shannon, a research assistant in the Electrical Engineering

Department at M.I.T., proposed the basic principles of Boolean

algebra.

T F 3. In the absence of parentheses, the AND operation takes precedence

over the OR operation.

T F 4. Logical functions are implemented by the interconnection of

decoders.

T F 5. The delay by the propagation time of signals through the gate is

known as the gate delay.

T F 6. A combinational circuit consists of n binary inputs and m binary

outputs.

T F 7. Any Boolean function can be implemented in electronic form as a

network of gates.

T F 8. A Boolean function can be realized in the sum of products (SOP)

form but not in the product of sums (POS) form.

T F 9. “Don’t care” conditions are when certain combinations of values of

variables never occur, and therefore the corresponding output

never occurs.

T F 10. The value to be loaded into the program counter can come from a

binary counter, the instruction register, or the output of the ALU.

T F 11. In general, a decoder has n inputs and 2ⁿ outputs.

T F 12. Combinational circuits are often referred to as “memoryless”

circuits because their output depends only on their current input

and no history of prior inputs is retained.

T F 13. Binary addition is exactly the same as Boolean algebra.

T F 14. Events in the digital computer are synchronized to a clock pulse

so that changes occur only when a clock pulse occurs.

T F 15. A register is a digital circuit used within the CPU to store one or

more bits of data.

MULTIPLE CHOICE

1. The operand ________ yields true if and only if both of its operands are true.

A. XOR B. OR

C. AND D. NOT

1. The operation _________ yields true if either or both of its operands are true.

A. NOT B. AND

C. NAND D. OR

1. The unary operation _________ inverts the value of its operand.

A. OR B. NOT

C. NAND D. XOR

1. A _______ is an electronic circuit that produces an output signal that is a simple Boolean operation on its input signals.

A. gate B. decoder

C. counter D. flip-flop

1. Which of the following is a functionally complete set?

A. AND, NOT B. NOR

C. AND, OR, NOT D. all of the above

1. For more than four variables an alternative approach is a tabular technique referred to as the _________ method.

A. DeMorgan B. Quine-McCluskey

C. Karnaugh map D. Boole-Shannon

1. ________ are used in digital circuits to control signal and data routing.

A. Multiplexers B. Program counters

C. Flip-flops D. Gates

1. ________ is implemented with combinational circuits.

A. Nano memory B. Random access memory

C. Read only memory D. No memory

1. The ________ exists in one of two states and, in the absence of input, remains in that state.

A. assert B. complex PLD

C. decoder D. flip-flop

1. The ________ flip-flop has two inputs and all possible combinations of input values are valid.

A. J-K B. D

C. S-R D. clocked S-R

1. A _________ accepts and/or transfers information serially.

A. S-R latch B. shift register

C. FPGA D. parallel register

1. Counters can be designated as _________.

A. asynchronous

B. synchronous

C. both asynchronous and synchronous

D. neither asynchronous or synchronous

1. CPUs make use of _________ counters, in which all of the flip-flops of the counter change at the same time.

A. synchronous B. asynchronous

C. clocked S-R D. timed ripple

1. The _________ table provides the value of the next output when the inputs and the present output are known, which is exactly the information needed to design the counter or any sequential circuit.

A. excitation B. Kenough

C. J-K flip-flop D. FPGA

1. A _________ is a PLD featuring a general structure that allows very high logic capacity and offers more narrow logic resources and a higher ration of flip-flops to logic resources than do CPLDs.

A. SPLD B. FPGA

C. PAL D. PLA

SHORT ANSWER

1. The digital circuitry in digital computers and other digital systems is designed, and its behavior is analyzed, with the use of a mathematical discipline known as __________.
2. The basic logical operations of Boolean algebra are AND, OR, and ________.
3. The fundamental building block of all digital logic circuits is the _______.
4. Each gate is defined in three ways: graphic symbol, algebraic notation, and __________.
5. To ________ a signal is to cause a signal line to make a transition from its logically false (0) state to its logically true (1) state.
6. A ________ is an interconnected set of gates whose output at any time is a function only of the input at that time.
7. A combinational circuit can be defined by Boolean equations, truth table, and _________.
8. Consisting of an array of 2” squares representing all possible combinations of values of n binary variables, the _________ is a convenient way of representing a Boolean function of a small number (up to four) of variables.
9. The _________ connects multiple inputs to a single output.
10. A _________ is a combinational circuit with a number of output lines, only one of which is asserted at any time.
11. The simplest form of sequential circuit is the _________.
12. A ________ is a register whose value is easily incremented by 1 modulo the capacity of the register.
13. An asynchronous counter is also referred to as a ________ because the change that occurs to increment the counter starts at one end and “ripples” through to the other end.
14. A _________ is a relatively small PLD that contains two levels of logic, an AND-plane and an OR-plane, where both levels are programmable.
15. Also referred to as a field-programmable device (FPD), a __________ refers to any type of integrated circuit used for implementing digital hardware, where the chip can be configured by the end user to realize different designs.