CHAPTER 7: The CPU And Memory

Question 1

The Little Man instruction set is based on a decimal number system; real computers encode instructions and data using the

a) binary system.
b) Unicode system.
c) decimal system.
d) algebraic system.

Answer 1

a) binary system.

Question 2

The ALU and CU together are known as the

a) CPU.
b) instruction set.
c) program counter.
d) Memory Management Unit.

Answer 2

a) CPU.

Question 3

The area inside of the CPU that holds data temporarily and performs calculations is called the

a) accumulator.
b) program counter.
c) arithmetic logic unit.
d) Memory Management Unit.

Answer 3

c) arithmetic logic unit.

Question 4

The storage locations that are used for a particular defined purpose within the CPU are called

a) RAM.
b) storage.
c) the bus.
d) registers.

Answer 4

d) registers.

Question 5

The 1-bit registers that are used to allow the computer to keep track of special conditions (like overflow or power failure) are often called

a) flags.
b) loops.
c) the ALU.
d) I/O counters.

Answer 5

a) flags.

Question 6

Loading the value zero into a register is called

a) inverting a register.
b) clearing a register.
c) dumping the register.
d) incrementing a register.

Answer 6

b) clearing a register.

Question 7

The register that holds the address of the memory location that needs to be accessed is called the

a) IR.
b) MAR.
c) MDR.
d) MBR.

Answer 7

b) MAR.

Question 8

The register that holds the current instruction is called the

a) IR.
b) PC.
c) LMC.
d) MBR.

Answer 8

a) IR.

Question 9

The register that will hold the data value that is being transferred between the CPU and a particular memory location is called the

a) PC.
b) ALU.
c) MAR.
d) MDR.

Answer 9

d) MDR.

Question 10

The mailboxes in the LMC model are the equivalent to a real computer’s

a) CPU.
b) ports.
c) memory.
d) control unit.

Answer 10

c) memory.

Question 11

Which of the following is NOT one of the three lines that control the memory cell?

a) Skew line
b) Address line
c) Read/write line
d) Activation line

Answer 11

a) Skew line

Question 12

If the Memory address register is 8 bits wide, the number of possible memory addresses is

a) 8
b) 16
c) 64
d) 256

Answer 12

d) 256

Question 13

Memory that retains its values when power is removed is called

a) DRAM.
b) SRAM.
c) volatile.
d) nonvolatile.

Answer 13

d) nonvolatile.

Question 14

There would never be a reason for an address transfer from the ________ to another register within the CPU.

a) IR
b) PC
c) MAR
d) MDR

Answer 14

c) MAR

Question 15

When the instruction being executed is to store data, the data will be transferred from another register in the CPU to the _____, and from there it will be transferred into memory.

a) IR
b) PC
c) MAR
d) MDR

Answer 15

d) MDR

Question 16

The different ways of establishing memory addresses within an instruction are called

a) MAR codes.
b) MDR codes.
c) addressing modes.
d) programmable modes.

Answer 16

c) addressing modes.

Question 17

Flash Memory

a) is volatile.
b) is faster than standard RAM.
c) has unlimited rewrite capacity.
d) is nonvolatile.

Answer 17

d) is nonvolatile.

Question 18

The first step in the instruction cycle is

a) clear the accumulator.
b) fetch the instruction from memory.
c) decode the instruction in the accumulator.
d) copy the data from the MAR to the MDR.

Answer 18

b) fetch the instruction from memory.

Question 19

The physical connections that make it possible to transfer data from one location in the computer system to another are called

a) flags.
b) fibers.
c) buses.
d) peripherals.

Answer 19

c) buses.

Question 20

Optical conductors are

a) faster than electrical conductors.
b) cheaper than electrical conductors.
c) more common than electrical conductors.
d) all of the above.

Answer 20

a) faster than electrical conductors.

Question 21

A bus in which there is an individual line for each bit of data, address, and control is called a

a) wide bus.
b) serial bus.
c) parallel bus.
d) dedicated bus.

Answer 21

c) parallel bus.

Question 22

A bus that transfers data sequentially, one bit at a time using just a single line pair is called

a) a serial bus.
b) a single bus.
c) a narrow bus.
d) a sequential bus.

Answer 22

a) a serial bus.

Question 23

A bus line that is “one-way” is called

a) a simplex bus line.
b) a serial bus line.
c) a one-way bus line.
d) a sequential bus line.

Answer 23

a) a simplex bus line.

Question 24

A bus line that can carry data in both directions at the same time is called a

a) simplex bus line.
b) complex bus line.
c) full duplex bus line.
d) half duplex bus line.

Answer 24

c) full duplex bus line.

Question 25

The exposed connectors into which external cables can be plugged are often called

a) plugs.
b) lines.
c) ports.
d) stacks.

Answer 25

c) ports.

Question 26

A bus that carries signals from a single specific source to a single specific destination is a(n)

a) simplex bus.
b) broadcast bus.
c) Ethernet bus.
d) point-to-point bus.

Answer 26

d) point-to-point bus.

Question 27

Virtually every bus internal to the CPU is

a) serial.
b) cables.
c) optical.
d) parallel.

Answer 27

d) parallel.

Question 28

Instructions that only the operating system can execute are called

a) system instructions.
b) executive instructions.
c) privileged instructions.
d) administrative instructions.

Answer 28

c) privileged instructions.

Question 29

Programs that execute without privileges are said to execute

a) in user space.
b) in data mode.
c) in kernel space.
d) in privilege space.

Answer 29

a) in user space.

Question 30

Multimedia applications, like modifying an image, often use

a) PSW instructions.
b) Flash instructions.
c) MMD instructions.
d) SIMD instructions.

Answer 30

d) SIMD instructions.

Question 31

The sources and destinations of data for an instruction are known as

a) Op codes.
b) Operands.
c) Op registers.
d) Operation fields.

Answer 31

b) Operands.

Question 32

Increasing the number of bits available for the op code in an instruction word

a) increases the demand on the CPU.
b) increases the number of memory locations that can be addressed.
c) increases the number of instructions available in the instruction set.
d) has no impact on any of the above.

Answer 32

c) increases the number of instructions available in the instruction set.