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10/15 10/8 OS作業
名稱	10/8 OS作業
日期	10/15
課程名稱	作業系統
指導教師	劉艾華

ONE.
Q1:The caches can process and retrieval data faster.

Q2:Caches solve the transfer problem by providing a buffer of intermediate speed between the components.

Q3:The data in the cache must be kept consistent with the data in the components. If a component has a data value change, and the datum is also in the cache, the cache must also be updated.

Q4:A component may be eliminated by an equal-sized cache, but only if:
a)The cache and the component have equivalent state-saving capacity.
b)Faster storage tends to be more expensive,if you want to use it,you nees afford.

TWO.
Q1:An interrupt handler is summoned to deal with the cause of the interrupt; control is then returned to the interrupted context and instruction.

Q2:An interrupt is a hardware-generated change-of-flow within the system.

Q3: A trap is a software-generated interrupt. An interrupt can be used to signal the completion of an I/O to obviate the need for device pooling. A trap can be used to call operating system routines or to catch arithmetic errors.

THREE.
Q1:
Device Controller
1.Stops and starts the activity of the peripheral device.
2.Generate error checking code.
3.Checks the error in the data recieved from the interface.
4.Abort that command which have errors.
5.Retry the command having an error.
6.Recieves the control signals from the interface unit.
7.Convert the format of the data.
8.Checks the status of the device.

CPU
1.A CPU retrieves information from the code within programs.
2.It reads it to understand what the code is for, and then it executes the instructions.

Both of them read the code and execute.

FOUR.
user's process-->Device drivers-->Interrupt processing program-->Transfer hard disk data

更新日期：2015/10/15 上午 12:46:45