→ BenLinus:第二題indirect的load,址20的內容放了值40, 址40的值是60 02/16 10:02
→ BenLinus:第一題我用回的好了 02/16 10:04
→ Karena1983:啊～我犯傻了，第二題的那個好簡單，沒仔細看 02/16 10:54
→ Karena1983:考試若這樣就糟糕了 (這題我學到的是該細心點 =0=) 02/16 10:55
這是高點汪兆慶 計算機組織/結構 經典題型解析 第六章 <指令集> 的題目
Q1:
The top of a memory stack contains 3350.
The stack pointer SP contains 3240.
A two-word procedure call instruction is located in memory at address 2000,
followed by the address field of 4385 at location 2001.
What are the contents of PC , SP , and the top of the stack :
(一) Before the call instruction is fetched from memory.
(二) After the call instruction is executed.
(三) After the return from the procedure.
A:
(一) PC = 2000 , SP = 3240 , top of stack = 3350
(二) PC = 4385 , SP = 3239 , top of stack = 2002
(三) PC = 2002 , SP = 3240 , top of stack = 3350
(一) 很trivial 就不用多解釋
(二)、(三) 就不懂了，希望高手能指教這題的觀念
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Q2:
Given the memory values in Table 1 and a one-address machine with an
accumulator, what value do the following instructions load into the
accumulator ?
Address Content
(一) LOAD INDIRECT 20 20 40
(二) LOAD DIRECT 30 30 50
(三) LOAD IMMEDIATE 30 40 60
50 70
< Table 1 >
A:
(一) 60
(二) 50
(三) 30
我不懂的是為什麼 (一) 的答案是 60 呢？
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※ 編輯: Karena1983 來自: 221.169.157.105 (02/16 09:22)