Goal 1.2 Computer System

Question 1

Processor:
CPU (Central Processing Unit):
“Brains” of the computer
Executes ______
Fetch instruction from memory
Examine
Execute one after the other
Data transferred between components on a ____

Answer 1

programs
bus

Question 2

Processors:
Components of CPU

Answer 2

ALU

Registers
- High speed
- Holds one number of some bits
- Usually same size, but some have specialized functions
- Program Counter
- Instruction Register

Control Unit

Question 3

Data Path consists of:

Answer 3

Registers

ALU
- Mathematical operations
- Boolean operations

ALU Input Registers

ALU output register

Question 4

Instruction type:
Register-Memory

Data fetched from memory to _____

Data ______ in memory from register

Answer 4

register
stored

Question 5

Instruction type:
Register-Register

Data fetched from 2 registers

Manipulated in _____

Stored back in another/same _______

Data path cycle

Multiple ALU’s

Answer 5

ALU
register

Question 6

Instruction Execution

1. Fetch the next ______ from memory into the instruction register
2. Change the program ______ to point to the next instruction
3. Determine the type of instruction just fetched
4. If instruction uses a word in memory, determine where it is
5. Fetch the _____, if needed, into a CPU register
6. Execute the instruction
7. Return to step __

Answer 6

instruction
counter
word
1

Question 7

RISC
Reduced Instruction Set Computer

Around 50 instructions

Each does less, but executes much ____.

Hardware implementation with no translation

Phones, IOT, things not worried about ____ ______.

Lower power consumption

Answer 7

faster
backwards compatibility

Question 8

CISC
Complex Instruction Set Computer

______ of instructions

Each instruction slower to execute, but does more

___/____ ____ computers
- Have RISC core as compromise

Backwards compatibility keeps it alive

Answer 8

Hundreds
Intel/AMD x86

Question 9

Design Principles for Modern Computers

All instructions directly executed by _____

Maximize rate at which instructions are issued

Instructions should be easy to ____

Only loads and stores should _____ memory

Provided plenty of ______

Answer 9

hardware
decode
reference
registers

Question 10

Pipelining

Answer 10

Allows for multiple instructions to be executed at once.

Question 11

Longer pipelines

Answer 11

allow for smaller chunks

more instructions being executed

Higher Mhz/Ghz

May have to clear pipeline more often

Question 12

smaller pipelines

Answer 12

bigger chunks

lower Mhz/Ghz

Can be more efficient

Question 13

Primary Memory

Stores programs and data

Stored in 1’s and 0’s (bit)

uses ____/_____ to store multiple bits assigned to one address

Each cell has the same number of ____

Answer 13

cells/locations
bits

Question 14

Less bits/cell ⇒ more memory addresses ⇒

Answer 14

larger instructions

Question 15

more bits/cell ⇒ less memory addresses ⇒ smaller instructions ⇒

Answer 15

Wasted memory

Question 16

32bit computer ⇒ 232 memory addresses ⇒

Answer 16

4,294,967,296 bytes of memory.

Question 17

frequently used data is stored in ______

Answer 17

cache

Question 18

Memory hierarchy/ Memory pyramid:
Registers
____
Main Memory
Magnetic or solid state disk
___/____ disk

Answer 18

Cache
Tape/ Optical

Question 19

the most important component of a computer system. A control unit is a part of the CPU.

Answer 19

Central processing unit

Question 20

controls the operations of all parts of the computer but it does not carry out any data processing operations.

Answer 20

control unit

Question 21

directs the operation of the processor. It was included as part of the Von Neumann Architecture

Answer 21

control unit

Question 22

It is the responsibility of the control unit to tell the ____ _____, arithmetic/logic unit, and input and output devices how to respond to the instructions that have been sent to the processor

Answer 22

computer’s memory

Question 23

It is the responsibility of the control unit to tell the computer’s memory, arithmetic/logic unit, and input and output devices how to respond to the instructions that have been sent to the processor.

It fetches ______ instructions of the programs from the main memory to the processor instruction register, and based on this register contents, the control unit generates a ____ _____ that supervises the execution of these instructions.

Answer 23

internal
control signal

Question 24

A control unit works by receiving input information which it converts into ____ _____, which are then sent to the central processor. The computer’s processor then tells the attached hardware what operations to perform. The functions that a control unit performs are ______ on the type of CPU because the architecture of the CPU varies from manufacturer to manufacturer.

Answer 24

control signals
dependent

Question 25

devices that require a CU (Control Unit) are:

Answer 25

Control Processing Units(CPUs)
Graphics Processing Units(GPUs)

Question 26

Functions of the control unit:

It coordinates the sequence of data movements into, out of, and between a processor’s many ____.

It interprets _____.

It controls data flow inside the processor.

Answer 26

sub-units
instructions

Question 27

Functions of the control unit:

It receives _____ instructions or commands to which it converts to sequence of control signals.

It controls many _______ units(i.e. ALU, data buffers and registers) contained within a CPU.

It also handles multiple tasks, such as _____, decoding, execution handling and storing results.

Answer 27

external
execution
fetching

Question 28

There are two types of control units:

Answer 28

Hardwired

Micro programmable control unit.