CO1 WEEK 4 PARTS OF CPU

Question 1

What are transistors?

Answer 1

• Connected by busses
• Tiny electronic switch
• Can be turned of by applying voltage to their terminals
• Arranging transistors in different ways = logic gates and circuits that preform operations
• moore’s law=number of transistors double each year

Question 2

What are processors?

Answer 2

Processors speed
- clock speed =instructions per second
- cpu requires fixed amount of clock cycles
- Faster clock speed more instructions

Question 3

What are the main parts of the CPU?

Answer 3

-Control unit
-ALU
-Registers

Question 4

What is the CU?

Answer 4

Co ordinates the activity of all processor components
- decided instruction’s received
- manages the phases of FDE

Question 5

What is the ALU?

Answer 5

carries out calculations and logic
- includes eg +-x,divide
-logic <>
- Stored in Accumulator

Question 6

What are registers and state their function?

Answer 6

• Small areas of volatile memory in cpu
• temporary store for data
• very fast
• when data processed, values shifted in and out

Question 7

What are the names of the registers?

Answer 7

PC
-CIR
-MAR
-MDR
-ACC

Question 8

What is the PC?

Answer 8

Stores the address of memory location that data is about to be written to or read from.

Question 9

What is the MAR?

Answer 9

• Temporarily stores address of memory location of data
  Eg address of next instruction (copied from PC)

Question 10

What is MDR/MBR?

Answer 10

• Contains the contents of the memory address specified by MAR

Question 11

What is the CIR?

Answer 11

stores the instruction that is currently being decoded or executed or copied from MDR
- split into 2
first part is Operation code which decoded for CU
the second part is data or address of data which sent to MAR

Question 12

What is the ACC?

Answer 12

holds data while it’s being processed
-stores all input/output as well as results of calculations

Question 13

What are the key parts of Von Neumann architecture ?

Answer 13

single control unit
- linear
- program and data stored together
- same bus for data and instruction
- FDE used
- fetches data or instruction one at a time

Question 14

What are the probs with VN architecture?

Answer 14

Shared memory- can cause corruptions
- memory leaks
- bottle necks
- Fetch rate

Question 15

What is the key Parts of Harvard architecture?

Answer 15

Units dif sizes better use of memory
- different word lengths for dif units
- Instructions more likely read only
- multiple cores on one task

Question 16

What are the problems with H architecture?

Answer 16

Physical space
- complexity

Question 17

What are the Key features of CISC?

Answer 17

Many instructions available = multiple cycles
- complex design
- more transistors = higher cost
- less use of RAM
- Variable n of bytes as instructions are longer

Question 18

What machines use CiSC?

Answer 18

desktop, computer

Question 19

What are the key features of RISC?

Answer 19

limited instruction
- once cycle
- simple design
- less transistors
- less cost
- heavy use of ram
- Fixed num of bytes

Question 20

What machines use RISC?

Answer 20

Smartphones and tablets

Question 21

What is SISD?

Answer 21

Single instruction single data
- pipeline
- inside CPU

Question 22

What is SIMD?

Answer 22

Single instruction Multiple data
- array processing
- graphics cards , game consoles

Question 23

What is MIMD?

Answer 23

Multiple instruction Multiple Data
- multicore
- super computers
- multicore chips

Question 24

What is pipelining?

Answer 24

Staggers FDE cycle into 3 or more processing paths

Question 25

What is array processing?

Answer 25

Data processed individually