Ch. 1 PPT Flashcards
What does an OS do?
Exploits processor HW resources, provides a set of system services, and manages secondary memory and IO devices
Basic components of a PC
Processor, main memory, IO modules, and the System Bus
What does the processor do?
Control operation of the computer and performs data processing
What is main memory?
The temporary memory, it is wiped clean every time the system shuts down.
What do IO modules do?
Move data between computer and external environments… HDD, communications equipment, and terminals
What does the System bus do?
Provides communication among processors, main memory, and IO modules
What is a microprocessor?
An invention that brought about desktop and handheld computing. The processor is on a single chip and it is fast for general purpose.
What is a GPU?
Does computation on single instruction multiple data techniques. Used for numerical processing, physics simulation, and computations on large data sets.
What is a Digital Signal Processor?
Handles streaming signals. Used to be found in modems,. Can decode and encode speech and video (codecs).
What is a system on a chip?
DSP, GPU, main memory, CPUs, and caches on one chip for mobile devices
How does a processor execute an instruction?
Fetches the instruction from memory and executes it
What does the program counter do?
Hold the address of the next instruction
What does the instruction register do?
Holds the current instruction. it is interpreted and then executed.
What would a control operation be?
Changing the order in which instructions are to be executed.
What is an interrupt?
Something that changes the execution by the processor. Aimed at making things more efficient
Program Interrupt
Usually caused by an execution error, like and overflow or a divide by zero
Timer Interrupt
Generated by a timer in the processor. Allows the OS to do something on a regular interval.
IO Interrupt
Sent to the processor by an IO device, can be an error or signaling that something was completed successfully.
Hardware Failure Interrupt
Caused when there is a hardware failure like bad memory or a power failure
What happens if there are multiple interrupts?
Disable interrupts while another interrupt is being process, or implement an interrupt hierarchy
What are some memory constraints?
It’s expensive, and its speed: meaning it has to be able to keep up with the processor.
What is the general trade off of memory?
The more you have, the slower it is. The less you have, the more expensive it is but its faster
What is Locality?
Putting clusters of data into levels, such that the higher levels are accessed more frequently than the lower levels.
What is secondary memory?
The more permanent memory, like a hard disk.
