Page 83 - Computer_Science_F5
P. 83
Computer Science complexity. Research the cost staff’s immediate response (handling
the fire). Interrupts are signals generated
implications of implementing DMA
by external devices or internal hardware
controllers in computer systems.
components that require the processor’s
How does this cost factor into
immediate attention. These signals
decisions about using DMA?
FOR ONLINE READING ONLY
3. Research and discuss specific temporarily halt the processor’s current
task and divert its focus to handling the
examples of how DMA technology interrupt. Examples of interrupts are; a
is utilised in various fields key being pressed on the keyboard and
like networking, multimedia, a network card receiving data. Different
scientific computing, or real-time interrupts can have varying priorities. Just
data processing. Prepare a short as a fire alarm takes precedence over a
presentation highlighting these customer placing an order, high-priority
real-world applications and their interrupts (like hardware failures) preempt
significance. lower-priority ones (like keyboard input).
4. Simulate a simple DMA transfer
scenario using a flowchart or Exceptions
pseudocode, outlining the steps Exceptions are like the head chef noticing
involved from processor initiation smoke coming from the oven (an error
to data transfer completion. condition). This unexpected situation
requires the chef’s attention to diagnose
Interrupt and exception and fix the problem (handle the exception).
The restaurant analogy we used for I/O Exceptions are internal events generated
by the processor itself during program
systems also applies to interrupts and execution. These events can be errors
exceptions in computer architecture. (like division by zero), privilege violations
Imagine the well-coordinated restaurant (attempting to access unauthorised
staff working diligently. While the chefs memory), or other unexpected conditions
(processor) focus on preparing meals that require the processor’s intervention.
(computations), unexpected events The processor has built-in mechanisms
can occur, requiring their immediate to handle exceptions. These mechanisms
attention. These events are analogous to typically involve saving the processor’s
interrupts and exceptions in a computer state, identifying the exception type,
system. and executing specific code (exception
handler) to address the issue.
Interrupts
An interrupt is like a fire alarm going Context switching
off in the restaurant. This disrupts the Both interrupts and exceptions involve
normal workflow and demands the context switching, where the processor
74
for Advanced Secondary Schools
Computer Science Form 5.indd 74 23/07/2024 12:32
