Computer Organisation & Architecture

Question 1

When the processor writes data to the main memory it will make use of the address, control and data buses.
Explain how each of these buses will be used during this write process.

[4 marks]

Answer 1

• The address of the memory to be written to is placed on the address bus (by the processor);
• The data to be written is placed on the data bus
• The signal to write is placed on the control bus
• The control bus carries a clock signal (to synchronise the memory and processor)
• When the write signal is received (by the memory) on the control bus; the data from the data bus is stored; into the location identified by the address bus

Exam Q

Question 2

Give situations where Harvard architecture may be used.

Answer 2

• Digital signal processing
• Embedded devices
• Microprocessors / microcontrollers

Question 3

Describe and explain the process with which data is originally saved onto a read only optical disk and how this is read by a consumer.
(3 marks)

Answer 3

• Pits & Flats are stamped into aluminium layer (by special machine)
• Laser in disk drive reads ‘pits’ and ‘flats’
• ‘pits’ represent 0s and ‘flats’ represent 1s.
• Reads as binary values.