mcq 隊列

Question 1:

問題1：

A string is a collection of characters. Each Character is an of byte length which is stored at successive locations. In the 8086 microprocessor, which characters are considered in the string?

字符串是字符的集合。 每個字符都有一個字節長度，存儲在連續的位置。 在8086微處理器中，字符串中應考慮哪些字符？

1. EBCDIC characters

   EBCDIC字符

2. ASCII characters

   ASCII字符

3. A string does not treat characters

   字符串不處理字符

4. None of the above

   以上都不是

Answer: a. ASCII characters

答： ASCII字符

Explanation:

說明：

In the 8086 microprocessor's assembly language, the String is the collection of ASCII characters.

在8086微處理器的匯編語言中，字符串是ASCII字符的集合。

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Question 2:

問題2：

While performing any of the MOVE instructions over Strings, i.e. MOVSB, MOBSW or MOVSD, by default, the data is transferred from -

默認情況下，在通過字符串執行任何MOVE指令時，即MOVSB，MOBSW或MOVSD，數據將從-

1. DS:SI to ES:DI

   從DS：SI到ES：DI

2. ES:DI to DS:SI

   ES：DI到DS：SI

3. ES:SI to DS:DI

   ES：SI至DS：DI

4. None of the above

   以上都不是

Answer: a. DS:SI to ES:DI

答： 從DS：SI到ES：DI

Explanation:

說明：

By default, every move instruction transfers data from the address calculated from DS register and contents of SI to the address calculated from ES register the contents of DI, i.e. from DS: SI to ES: DI.

默認情況下，每條移動指令都將數據從DS寄存器計算出的地址和SI的內容傳輸到DI內容從ES寄存器計算出的地址，即從DS：SI到ES：DI。

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Question 3:

問題3：

Which of the following is the correct code for repeating the MOVSB instructions 10 times?

以下哪項是將MOVSB指令重復10次的正確代碼？

1. REPEAT MOVSB 10

   重復MOVSB 10

2. REP 10 MOV SB

   REP 10 MOV SB

3. CX=10

   CX = 10

   REP MOVSB

   REP MOVSB

4. None of the above

   以上都不是

Answer: c. CX =10 REP
MOVSB

答：c。 CX = 10代表
MOVSB

Explanation:

說明：

REP instruction repeats the given instruction(s) till CX does not becomes zero, i.e. CX != 0. So, for executing the mentioned instruction 10 times, we need to initialize the CX register with 10.

REP指令重復給定的指令，直到CX不為零，即CX！=0。因此，要執行上述指令10次，我們需要將CX寄存器初始化為10。

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Question 4:

問題4：

Which of the following flags gets affected when a compare instruction, i.e. CMPSB, CMPSW or CMPSD is executed?

當執行比較指令(即CMPSB，CMPSW或CMPSD)時，以下哪個標志受影響？

1. Direction Flag (DF)

   方向旗(DF)

2. Trap Flag (TF)

   陷阱標志(TF)

3. Interrupt Flag (IF)

   中斷標志(IF)

4. Zero Flag (ZF)

   零標記(ZF)

Answer: d. Zero Flag (ZF)

答案：d。 零標記(ZF)

Explanation:

說明：

Whenever a compare instruction over strings is executed, the status flags are affected. From the mentioned options, only Zero Flag is a status flag. The rest are the Control Flags.

每當執行基于字符串的比較指令時，狀態標志都會受到影響。 從上述選項中，只有零標志是狀態標志。 其余的是控制標志。

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Question 5:

問題5：

At a time, on how many bits can we operate while performing any string operation?

一次，執行任何字符串操作時，我們可以操作多少位？

1. 8 bits

   8位

2. 16 bits

   16位

3. 32 bits

   32位

4. All of the above

   上述所有的

Answer: d. All of the above

答案：d。 上述所有的

Explanation:

說明：

The string operations can be performed either on 1 byte, 2 bytes or 4 bytes at a time. In the string instructions, for example, Move instructions, in MOVSB, 'B' stands for Byte, i.e. 8 bits. Similarly, in MOVSW, 'W' stands for a word, i.e. 16 bits and in MOVSD, 'D' stands for a double word, i.e. 32 bits.

可以一次在1個字節，2個字節或4個字節上執行字符串操作。 在字符串指令中，例如，MOVSB中的移動指令，“ B”代表字節，即8位。 同樣，在MOVSW中，“ W”代表一個字，即16位，在MOVSD中，“ D”代表一個雙字，即32位。

翻譯自: https://www.includehelp.com/embedded-system/mcq-string-manipulation-instructions-in-the-8086-microprocessor.aspx

mcq 隊列