Microprocessor Register Function
The core task of a microprocessor is executing instructions sequentially. To do this efficiently, it needs a mechanism to keep track of which instruction to execute next.
Instruction Fetching Process
During the instruction cycle, the microprocessor first needs to fetch the instruction from memory. The address of this instruction is crucial for the fetch operation.
Register Role in Fetching
Several registers are involved in microprocessor operations, but one specific register is dedicated to holding the memory address of the instruction that the processor will execute next. This process is fundamental to program execution flow.
Analyzing Register Options
- Accumulator: Primarily used to store data temporarily during arithmetic and logical operations. It does not hold instruction addresses.
- Program Counter (PC): This register holds the memory address of the next instruction to be fetched and executed. After fetching an instruction, the PC is automatically incremented to point to the subsequent instruction.
- Stack Pointer (SP): Manages the stack, a region of memory used for temporary storage, often for function calls and local variables. It points to the top of the stack.
- Instruction Register (IR): Holds the current instruction that has just been fetched from memory and is being decoded and executed. It does not hold the address of the *next* instruction.
Conclusion on Instruction Address
Based on the functions of these registers, the Program Counter is the specific register responsible for holding the address of the next instruction to be fetched from memory.
Similar Questions
- Calculate the output voltage of an op-amp for input voltages of $V_{i1} = 150 \mu\text{V}$ and $V_{i2} = 140 \mu\text{V}$. The amplifier has a differential gain of $A_d = 4000$ and the value of CMRR is $100$ :
- For an op-amp having a slew rate of $4\text{ V}/\mu\text{s}$, what is the maximum closed-loop voltage gain that can be used when input signal varies by $0.1\text{V}$ in $10\mu\text{s}$ ?
For the series diode configuration of the given figure, determine $V_D$ and $I_D$.
For the given emitter-bias network, determine the values of $I_C$ and $V_{CE}$. Assume $\beta = 100$.
- Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : The gate of a MOSFET is insulated from body of FET by deposition of a very thin fragile layer of $\text{SiO}_2$ over the substrate.
Reason (R) : The device is therefore called an insulated gate field-effect transistor (IGFET).
In the light of the above statements, choose the most appropriate answer from the options given below : - If 8085 microprocessor adds 87H and 79H, then :
- The content of register (B) and register (C) of 8085 microprocessor are 0AH and 0BH. It is desired to multiply the content of register B and register C and store the results in accumulator. A part of 8085 program for this purpose is given as :
MVI A, 00H
LOOP ; _ _ _ _ _
_ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _
HLT END
A sequence of instructions to complete the program would be : - The sequence of steps performed by microprocessor to fetch the data byte from memory :
A. The byte is placed in the instruction decoder of the microprocessor.
B. The byte from the memory location is placed on data bus.
C. The control unit sends the control signal $\overline{\text{RD}}$ to enable the memory chip.
D. The microprocessor places the 16-bit memory address from program counter on the address bus.
Choose the correct answer from the options given below : - Sequence of steps in 8085 microprocessor interrupt execution :
A. Interrupt acknowledged
B. Program counter content saved
C. Control transfered to ISR
D. Interrupt vector is read
Choose the correct answer from the options given below : - Consider the following statements regarding the 8085 microprocessor :
A. The 8085 is an 8-bit microprocessor.
B. It has a 16-bit address bus, allowing it to access 64 KB of memory.
C. It has 40 pins.
D. It uses a multiplexed address/data bus.
Choose the correct answer from the options given below :
Important Questions from Miscellaneous
- Which of the following scheduler/schedulers is/are also called CPU scheduler ?
(A). Short Term Scheduler
(B). Long Term Scheduler
(C). Medium Term Scheduler
(D). Asymmetric Scheduler
Choose the correct answer from the options given below: - A situation where two or more processes are blocked, waiting for resources held by each other is called:
- External fragmentation occurs ________.
- Which disk scheduling algorithm looks for the track closest to the current head position?
- Which CPU scheduling algorithm prefers the process with the shortest burst time?
