Preview

08 - Additional CPU Theory

 1. Watch the video below and fill in the blanks.
In this video the Raspberry Pi was made a bit faster
by ____________ the clock speed of the CPU.

Now there can be a problem with that, if 
you ______________[too high], you could:

>>cause system instability

>>the system might crash, 

>>it might overheat. 

Therefore there are advantages and disadvantages to overclocking. 

  decreashing / declock

  increasing / doubleclock

  increasing / overclock

  increasing / declock

 2. What is overclocking?

  decreasing the clock frequency so it is not 'over' the limit

  increasing the number of cores so that the clock speed is doubled or quadrupled, depending on the cores added

  adding a clock to increase the speed of the computer

  increasing the clock frequency to above it's recommended design speed - this can be done but requires some serious cooling systems!

 3. Parallel and multi-core processing both refer to the same thing: the ability to __________________________________ (in more than one core/CPU/machine.) So in this sense multi-core is just a means to do parallel processing.
parallelprocessing.jpg

  execute code at the same time

  to hold the data on multiple, parallel wires

  to run instructions in the ALU core

  read data and instructions together

 4. Analyse the "pipeline" below and fill in the blanks.
Instruction pipelining is a technique for implementing instruction-level 
parallelism within a single processor. 

Pipelining attempts to keep every part of the processor busy with some 
instruction by dividing incoming instructions into a series of sequential
steps (the eponymous "pipeline") performed by different processor units 
with different parts of instructions processed in parallel. 

It allows ______________________________________________________________, 
but may increase latency due to the added overhead of the pipelining
process itself.

*Latency is referring to the amount of time taken to traverse a system
pipeline.png

  faster CPU throughput than would otherwise be possible at a given clock rate

  equal CPU throughput

  lighter data passing through the system

  slower CPU throughput

 5. The image shows an Intel CPU with a math co-processor. What is a co-processor?
Additional information about a coprocessor
==========================================

Operations performed by the coprocessor may be floating point 
arithmetic, graphics, signal processing, string processing, 
encryption or I/O Interfacing with peripheral devices. 

By offloading processor-intensive tasks from the main processor, 
coprocessors can accelerate system performance. Coprocessors allow 
a line of computers to be customized, so that customers who do not 
need the extra performance do not need to pay for it.
coprocessor.JPG

  A coprocessor is a type of computer that operates much faster than traditional computers

  A coprocessor is when a CPU is placed underneath the ALU so that it can co-work more closely

  A coprocessor is an additional processor which works as ROM

  A coprocessor is a computer processor used to supplement the functions of the primary processor (the CPU)

 6. Describe how the CPU and RAM work together to make a tablet computer work and execute instructions/programs?

  Instructions currently running are stored in RAM - these are fetched by the CPU which then executes them

  Instructions currently running are stored in the ROM (Hard drive) - these are then executed by the RAM and CPU together

  Instructions are stored in the RAM and CPU and the ALU fetches them from the RAM to execute them.

  Instructions currently running are stored in the CPU - these are fetched by the RAM which executes them

 7. What is one of the key advantages of Cache memory?

  Data is held permanently by the Cache which makes it reliable

  Data does have to be fetched from RAM so it provides an additional place to fetch from

  Data does not have to be fetched from RAM so it speeds up the access

  Instructions are executed by the Cache which frees up the CPU

 8. Which of the following are key advances in memory technology that allow for significant improvement in the performance of certain devices - e.g. tablets.
#1 Smaller in Size
#2 Faster Access
#3 Larger CPUs
#4 Smaller Capacity
#5 Larger Capacity
#6 More durable
#7 Costs less per byte

  5,6

  3,4,5

  1,2

  1,2,5,6,7

 9. Using examples from the image above, what is an opcode? (You can also look up the term 'Operand' which is the data/value that is being operated on)
cpuoperand.png

  The python code required to carry out the instruction

  the binary code referring to a number that will be added to the ALU

  Part of the instruction that specifies what operation to be carried out (e.g. 00001000 = add to timer/00000100 = subtract from timer)

  The value on which the instruction operates e.g.0000010

 10. Explain how the CPU can determine whether it represents an instruction or data
#1 ==============
Instructions and data are fetched at different points in the
fetch execute cycle

#2 ==============
Instructions and data are kept in seperate parts of the memory
(by the operating system)

#3 ==============
The program counter points to the address of the instructions
instructionscpuinterpret.png

  #1 #2 and #3 are all correct

  None of the above are correct explanations

  #3 is the only correct option

  #2 is the only correct option

 11. Data and Instructions in use are stored in the:

  Hard Drive

  Embedded System

  Main Memory

  Processor

 12. What does NOT affect the performance of the computer?

  Number of Cores

  The number of instructions in a program

  Clock Speed

  Cache Size

 13. If the number of cores increases from two cores to four cores,what is the exact effect on performance?

  The maximum number of instructions executed per second quadruples

  performance decreases

  The maximum number of instructions executed per second is halved which increases performance

  The maximum number of instructions executed per second doubles

 14. If the processing speed goes up from 1GHZ to 4GHZ ? what is the exact effect on the performance of the computer?

  The maximum number of instructions executed per second quadruples

  The maximum number of instructions executed per second is quartered

  The maximum number of instructions executed per second doubles

  The maximum number of instructions executed per second is halved

 15. If the processing speed goes up from 2GHZ to 4GHZ and the number of cores goes from 2 to 4 ? what is the exact effect on the performance of the computer?

  The maximum number of instructions executed per second is halved

  The maximum number of instructions executed per second quadruples

  The maximum number of instructions executed per second doubles

  The maximum number of instructions executed per second is quartered

 16. If the processing speed goes from 1GHZ to 4GHZ and the processor is changed from an 8 core to a dual core processor ? what is the exact effect on the performance of the computer?

  The number of instructions executed per second quadruples

  The number of instructions executed per second is halved

  The number of instructions executed per second doubles

  The number of instructions executed per second stays the same

 17. What component holds the address of the next instruction

  Memory Address Register

  Memory Data Register

  Accumulator

  Program Counter

 18. Results of calculations are held in this register:

  Memory Address Register

  Program Counter

  Memory Data Register

  Accumulator

 19. This holds the instruction/data temporarily after it is brought to the processor from the main memory

  Memory Address Register

  Accumulator

  Program Counter

  Memory Data Register

 20. This holds the number of the current instruction being worked on

  Program Counter

  Accumulator

  Memory Address Register

  Memory Data Register

 21. This would perform an operation including the logic command/word ?And?

  Arithmetic Logic Unit

  Control Unit

  Cache

  Accumulator

 22. This would send a signal such as ?Memory Read?

  Arithmetic Logic Unit

  Accumulator

  Cache

  Control Unit

 23. This would perform an operation such as 5+8 (1-4)

  Control Unit

  Cache

  Accumulator

  Arithmetic Logic Unit

 24. This would reduce the number of memory/processor transfers

  Control Unit

  Accumulator

  Cache

  Arithmetic Logic Unit

 25. This sends signals such as ?I/O Read?

  Accumulator

  Cache

  Arithmetic Logic Unit

  Control Unit

 26. This sends signals such as ?Memory write?

  Accumulator

  Cache

  Arithmetic Logic Unit

  Control Unit

 27. This doesn?t happen during the Fetch part of the cycle:

  Status Register updated

  Instructions are transferred from Main Memory and Hard drive

  Results are held in the Accumulator

  Current Instruction is held in the CIR

 28. Which of the following is held in ROM?

  Data currently in used

  ROM instructions and clocks

  Instructions frequently used (ROM is the same as CACHE)

  Bootstrap loader

 29. What carries the address of the next instruction that will be fetched

  System Bus

  Data Bus

  Control Bus

  Address Bus

 30. One of the properties of an address bus is that it is uni-directional.

  TRUE

  FALSE