University of South Africa COS 2621 EXAM MEMO MERGED

COS2621 - Solutions to Past Papers
October / November 2012
Question 2(a) (5)
To improve performance, designers have turned to a fundamentally new approach to chip organization and
architecture, called multicore organization. Explain what this means and list four of the advantages of using
this approach.
Multicore - Multiple processors on the same chip - with a large shared cache.
• increases performance without increasing the clock rate;
• justifies much larger caches;
• results in lower power consumption and less heat generation;
• uses multiple simpler processors, rather than more complex one.
Question 2(b) (5)
List and describe the most common classes of interrupt.
• Program interrupts - occur as the result of the execution of an instruction, such as division by 0,
arithmetic overflow etc.
• Timer interrupts - generated by a timer within the processor. Allows the operating system to
perform certain functions on a regular basis.
• I/O interrupts - generated by an I/O controller, to signal the normal completion of an operation, or
an error condition.
• Hardware failure - generated by a power failure, or memory parity error.
Question 2(c) (4)
Use a table to make a comparison between at least four characteristics of a Large-Register-File (such as
those used in a RISC-type architecture) and those of a typical Cache Organization.