Bissoy.com
Doctors Medicines MCQs Q&A

Consider the following sequence of micro-operations. MBR ← PC MAR ← X PC ← Y Memory ← MBR Which one of the following is a possible operation performed by this sequence?

Consider the following sequence of micro-operations. MBR ← PC MAR ← X PC ← Y Memory ← MBR Which one of the following is a possible operation performed by this sequence? Correct Answer Initiation of interrupt service

The correct answer is "option 4".

CONCEPT:

Micro-operations are also known as micro-ops.

They are the atomic or functional operations of a processor.

It is an elementary Central Processing Unit (CPU) operations performed during one clock pulse.

Micro-operations are low-level instructions, used in some designs, to implement complex instructions.

Micro-operations generally perform data stored in one or more registers.

EXPLANATION:

1. Program counter holds the next instruction value to be executed.

Here, MBR <- PC means the value of the program counter will get stored in MBR.

2. MAR <- X means some address value X is storing in MAR so to access memory location X.

3. PC <- Y means storing new instruction value Y to the program counter to access new instruction.

4. Memory <- MBR means MBR register will store its value to Memory. This saves the previous value of PC to memory.

This sequence of instructions matches with Interrupt Service Routine (ISR) since the sequence of instructions saved the address of current instructions into memory.

Then started executing new address by loading new instruction value to Program counter.

Hence, the correct answer is “option 4”.

Additional Information

1. Instruction fetch means fetching the instruction.

2. Operand fetch means fetching the operands.

3. Conditional branch means the program will branch to another instruction after satisfying a condition.

Related Questions

Consider the following statements in order to perform a write operation into a specified memory location, the MDR and MAR: 1. The word to be stored into the memory location is first loaded by the CPU into MDR. 2. The address of the location into which the word is to be stored is loaded by the CPU into MAR. 3. A write signal is issued by the CPU. Which of the above statements are correct ? 
The given Bar Graph presents the sale of a particular brand of car by three showrooms, A, B and C (in multiples of 100) during the months Jan, Feb, Mar and Apr, 2016 If the cars sold by A and B are all found to be in perfect order, but the cars sold by C were found to be defective to the extent of 15% 10%, 8% and 6%, respectively in Jan, Feb, Mar and Apr 2016. Then what is the ratio of non-defective cars sold by C to that of all cars sold by A and B during Jan-Mar 2016?
With regard to computer memory, which of the following statement(s) is/are TRUE?  (A) Cache memory is 'volatile' memory. (B) Magnetic memory is 'volatile' memory.  (C) Flash memory is 'volatile' memory. (D) RAM is 'volatile' memory. Choose the correct answer from the option given below:
A shared variable x, initialized to zero, is operated on by four concurrent processes W, X, Y, Z as follows. Each of the processes W and X reads x from memory, increments by one, stores it to memory, and then terminates. Each of the processes Y and Z reads x from memory, decrements by two, stores it to memory, and then terminates. Each process before reading x invokes the P operation (i.e., wait) on a counting semaphore S and invokes the V operation (i.e., signal) on the semaphore S after storing x to memory. Semaphore S is initialized to two. What is the maximum possible value of x after all processes complete execution?
The given Bar Graph presents the sale of a particular brand of car by three showrooms, A, B and C (in multiples of 100) during the months Jan, Feb, Mar and Apr, 2016 What is the ratio of number of cars sold by A in Jan-Feb, 2016 to that of cars sold by B during Mar-Apr, 2016?
Consider a process executing on an operating system that uses demand paging. The average time for a memory access in the system is M units if the corresponding memory page is available in memory, and D units if the memory access causes a page fault. It has been experimental measured that the average time taken for a memory access in the process is X units. Which one of the following is the correct expression for the page fault rate experienced by the process?
Consider the following statements: 1. Better memory utilization is possible with non-contiguous allocation using fixed size pages 2. Associative memory is used for providing fast access to data stored in cache memory. 3. Direct mapping of cache memory is hard to implement Which of the above statements are correct?
Consider the following statements about the doctrine of frustration:
1. Act has become impossible to be performed.
2. Act cannot be performed because of application of some law recently enacted.
3. Act cannot be performed because of the non-availability of raw material.
4. Act cannot be performed by defendant due to his accident.
Which of the statements given above are correct?
Which one of the following is true with regard to a CPU having a single interrupt request line and single interrupt grant line? i) Neither vectored nor multiple interrupting devices is possible. ii) Vectored interrupts is not possible but multiple interrupting devices is possible. iii) Vectored interrupts is possible and multiple interrupting devices is not possible. iv) Both vectored and multiple interrupting devices are possible.
Which of the following statement about computer memory are true?  A. Secondary storage is non-volatile storage.  B. Video memory found in graphics cards is volatile memory.  C. Primary memory (RAM) is the fastest form of memory in a computer.  Choose the correct answer from the options given below: