• Types Of Processor

Question 1

What are contemporary processor architectures?

Answer 1

• CPU chips which incorporate aspects of both von Neumann and Harvard architecture

Question 2

What are some features of contemporary processor architectures?

Answer 2

• One main memory for holding both data and instructions

* CPU cache memory is divided into an instruction cache and a data cache.

Question 3

Where are features of von neumann present in contemporary processor architecture?

Answer 3

• One main memory for holding both data and instructions

Question 4

Where are features of Harvard architecture present in contemporary processor architecture?

Answer 4

• Harvard architecture is used where the CPU accesses the cache, instructions and data are retrieved using Harvard architecture
• Cache memory is divided into an instruction cache and a data cache

Question 5

What does RISC stand for?

Answer 5

Reduced instruction set computers

Question 6

How does RISC work?

Answer 6

• A minimum number of very simple instructions, each taking one clock cycle, are used to accomplish all the required operations in multiple general purpose registers.

Question 7

What does CISC stand for?

Answer 7

Complex Instruction Set Computers

Question 8

How does CISC work?

Answer 8

• A large instruction set is used to accomplish tasks in as few lines of assembly language as possible.
• Processor hardware is capable of understanding and executing the series of sub tasks that make up a single instruction.
• Complex instructions are built into the machine’s hardware.

Question 9

What are some advantages of CISC?

Answer 9

• Quicker to code programs
• Compiler has very little work to do to translate a high level language statement into machine code.
• Because code is relatively short very little RAM is required to store the instructions

Question 10

What are some advantages of RISC?

Answer 10

• Hardware is simpler to build with fewer circuits needed for carrying out complex instructions.
• Because each instruction takes the same amount of time, pipelining is possible.
• RAM is cheap, RISC use of RAM and software allows better performance processors at a lower cost.

Question 11

What are some disadvantages of RISC?

Answer 11

• Compiler has to more work to translate high level code into machine code.
• More RAM is required to store the machine code instructions.

Question 12

What are some disadvantages of CISC?

Answer 12

• Many specialised instructions have to be be built into the hardware, whilst only around 20% will be used in the average program.

Question 13

How do multi-core processors benefit the user?

Answer 13

• Multi core processors can distribute workload across multiple processor cores.
• This results in achieving a higher performance due to performing several tasks in parallel.
• These systems are known as parallel systems.

Question 14

What is a disadvantage to parallel systems?

Answer 14

• Software has to be written to take advantage of multiple cores.
• Maximising usage of the computing resources provided by parallel systems requires adjustments to both the operating system and to existing application software.

Question 15

What is a co processor?

Answer 15

An extra processor used to supplement the functions of the primary processor.

Question 16

What are some functions of the co processor?

Answer 16

• May be used to perform floating point arithmetic, graphics processing, digital signal processing and other various other functions.

Question 17

What is a disadvantage to co processors?

Answer 17

• Cannot be a general purpose processor with the ability to fetch its own instructions, carry out input/output operations and so on.
• Can only carry out a limited range of functions.

Question 18

What are the two main processor architectures?

Answer 18

• Von Neumann

* Harvard

Question 19

What are the two main types of instruction set?

Answer 19

• CISC

* RISC

Question 20

Where might harvard architectures be used?

Answer 20

• Specialist embedded systems and digital signal processing, where speed takes priority over the complexity of design.

Question 21

How does memory and word length differ between Von Nuemann and Harvard?

Answer 21

Harvard can use different sized memories and word lengths can be used for data and instructions.