Chapter 3 Hardware

Question 1

Need for secondary STorage

Answer 1

-to store files, data, programs long term

Question 2

Need for Primary storage

Answer 2

-to store files needed to boot system
-to store OS or any system software
-to store immidiate data being processed

Question 3

Embedded System

Answer 3

-microprocessir within a larger system that performs a specific task
-has memory ,input/output abilities and a processor
-integrated into a machine, not easily changed by user
-eg a system in washing machine that only controls cycle programs
-combination of hardware and software designed for a specific function
-does not have its own operating system
-does not require much processing power

Question 4

Disadvantages

Answer 4

-difficult to change of update firmware by user or take advantage of new technology
-cannot easily be adpated for other tasks
-difficult to update or repair so thrown away instead

Question 5

RAM

Answer 5

-primary memory
-stores currently running part of software
-either static or dynamic
-can store data about input output devices ,contents of buffer , or information about current process

Question 6

SRAM

Answer 6

transistors arranged as flipflops, more complex circuitry

-faster access time as it does not need to be refreshed
-used on CPU for performance(used in cache memory)
-has lower data density
-does not need to be refreshed, consumes less power

Question 7

DRAM

Answer 7

uses single transistors and capacitors, stores bits as charge

-costrs less per unit
-higher storage as more data stored per chip
-simpler design uses fewer transistors
-needs to be refreshed, has higher power consumption
-slower access time, used in main memory

Question 8

ROM

Answer 8

-primary memory
-stores BIOS or any necessary permanent data
-stores the kernel of operating system// part of OS
-PROM can only be setup once
-EPROM erased using UV light, needs to be removed from device, can be overwritten multiple times, must be entrely erased to write
-EEPROM erased using voltage , erase within device ,can be overwritten multiple times does not entirely have to be erased before rewriting , contents of firmware change easily

Use in Embedded systems
-used to store data that does not change
-data must be stored when device is powered off
-stores boot up instructions

Question 9

Control System

Answer 9

• ## uses feedback to produce action

Question 10

Importance of feedback

Answer 10

-ensure system operates within given criteria
-allows system output to affect system input
-allows conditions to be automatically adjusted

Question 10

Actuator

Answer 10

-generates signal//converts electrical energy to mechanical energy
-to produce an action in a specific sitaution