→ devilend:1 爆表沒錯 02/02 20:22
以下是 97 中興計算機系統的題目
(1)(b)
Convert the decimal number -520 into signed 10-bit binary number in the 2's
complement representation
我記得 如果是 10-bit 2的補數可以表現的數字不是 -2^9 ~ +(2^9-1)
題目要表示 -520 這樣不就破表了
還是我觀念錯誤??
(6)
In a virtual memory system,it takes 10ns to access a word in the cache.If a
word is main memory but not in the cache,30ns are needed to load it into the
cache,and then the reference to it is srarted again.If the word is not in
main memory,12ms are required to fetch the word from disk,followed by 30ns
to copy itto the cache,and then the reference is started again.
(a)
Let the cache hit ratio be 0.9 and the main-memory hit ratio be 0.6.
What is the average time (in ns)to access a referenced word in the system?
(b)
The operating system can improve the CPU utilization by trying to do
something else other idle for 12ms to wait for the required data to be load
from disc to the main memory.Explain how this process works.
上面這一大題 完全不知道如何下手....
(7)
Consider a cache memory system with the following properties:
(i) 32-bit physical address
(ii) 16 Bytes per cache block
(iii) 128 KB of data cache,which are2-way set associative
(a)
Indicate the length if each field in a physical address: tag, index,and block
offset
我想法是:
block offset : 16 = 2^4
index : 128 KB /16 B = 2^13 / 2 = 2^12
tag : 32 - 12 - 4 = 16
這樣對嗎?
還是我算錯了?
(b)
Draw a simplified block diagram of this cache system, and show how a memory
reference that is a hit in the cache is processed
這題就是畫圖給他 對嗎?
不好意思 小弟程度不好 還希望各位高手多多指導
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一切....
似乎都不再那麼重要....
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※ 編輯: lovefo 來自: 114.46.163.157 (02/02 20:05)