Fig 1.2 Classes of interrupts
Program Generated by some condition that occurs as a results of an instruction execution, such as arithmetic overflow, division by zero, attempt to execute am illegal machine instruction, and reference outside a user's allowed memory space.
Timer Generated by a timer within the processor. This allows the operating system to perform certain functions on a regular basis.
I/O Generated by an I/O controller, to signal normal completion of an operation or to signal a variety of error conditions.
Hardware failure Generated by a failure such as power failure or memory parity error.
Source: William Stallings (Date of access: 16 October 2017)
1.6 Memory Hierarchy
It is a concept that is used to describe different ways in which a computer handles information.
Memory hierarchy can be used to separate storage devices into a hierarchy depending on response time. The hierarchy levels can be distinguished by their capacity, speed and cost.
Fig 1.3 illustrates a typical memory hierarchy levels. As you move down the hierarchy the following happens.
• Decreasing cost per …show more content…
Cache is also a temporary storage memory. It is closer to the central processing unit and is even faster than the random access memory. Most of the instructions or data that are frequently used by the processor are stored in cache memory.
When a processor uses certain data for the first process, a copy of the instructions is stored in the cache memory. If the processor needs the same instructions for another process, it checks in the cache memory first and if found data is retrieved. This improves the working performance of the
Program Generated by some condition that occurs as a results of an instruction execution, such as arithmetic overflow, division by zero, attempt to execute am illegal machine instruction, and reference outside a user's allowed memory space.
Timer Generated by a timer within the processor. This allows the operating system to perform certain functions on a regular basis.
I/O Generated by an I/O controller, to signal normal completion of an operation or to signal a variety of error conditions.
Hardware failure Generated by a failure such as power failure or memory parity error.
Source: William Stallings (Date of access: 16 October 2017)
1.6 Memory Hierarchy
It is a concept that is used to describe different ways in which a computer handles information.
Memory hierarchy can be used to separate storage devices into a hierarchy depending on response time. The hierarchy levels can be distinguished by their capacity, speed and cost.
Fig 1.3 illustrates a typical memory hierarchy levels. As you move down the hierarchy the following happens.
• Decreasing cost per …show more content…
Cache is also a temporary storage memory. It is closer to the central processing unit and is even faster than the random access memory. Most of the instructions or data that are frequently used by the processor are stored in cache memory.
When a processor uses certain data for the first process, a copy of the instructions is stored in the cache memory. If the processor needs the same instructions for another process, it checks in the cache memory first and if found data is retrieved. This improves the working performance of the