what is an interrupt?
a signal that is sent to the processor to request its immediate attention
what happens when the processor receives the interrupt
it suspends what it is doing and runs the process associated with the interrupt
what things can an interrupt caused by
- a hardware device has data ready to process
- a device has completed a task it was asked to do
- a process needs a function to be performed
- pre-set timer has expired
- hardware failure has occurred
what will the OS have relating to interrupts
Interrupt Service Routines (ISR or Interrupt Handlers)
what is the ISR
a small program designed to respond to each interrupt provided by either OS or I/O device drivers
what happens when an ISR is serviced?
the normal FDE cycle is affected
what happens to the FDE cycle
- the currently running process needs to be paused
- ISR run
- process is resumed
what is a volatile environment?
a snapshot of all the info needed to execute a process from its current instruction
what does a volatile environment contain?
SPR and GPR (including PC)
what does SPR stand for
special purpose register
what does GPR stand for
general purpose register
what does PC stand for
program counter
what does OS stand for
operating system
what does ISR stand for
interrupt service routines
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fetch, decode, execute9
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structure of the processor38
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infix and postfix19
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computer architecture57
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types of numbers32
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factors affecting processor performance37
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boolean laws and algebra identities20
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processor interrupts14
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subroutines, structures and built-in functions18
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logic gates25
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storing objects, stack and heap27
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memory allocation19
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network protocols58
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function stubs and passing parameters6
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computer networks31
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packet switching18
