Embedded Processors Interview Questions & Answers

Question 1. What Is Microprocessor?

Answer :

Microprocessor is a CPU fabricated on a single chip program controlled device, which fetched the instructions from memory, decodes and execute the instructions. Three basic characteristic differentiate microprocessor.

• Instruction Set: The set of instruction microprocessor can execute.
• Bandwidth: The number of bit’s processed in a single instruction
• Clock Speed: Given in MHz Megahertz, the clock speed determines how many instructions per second the processor can execute.

In addition to this, microprocessors are classified as being RISC (Reduced Instruction Set Computer) or CISC (Complex Instruction Set Computer).

Question 2. What Are The Basic Units Of Microprocessor?

Answer :

The basic units or block of microprocessor are ALU, an Array of Registers and control unit.

Question 3. Give Examples For8/16/32-bit Microprocessor?

Answer :

• 8-bit Processors- 8085, Z80, 6800
• 16-bit Processors- 8086, 68000, Z8000
• 32-bit Processors- 80386, 80486
• 64-bit Processors- Intel 64(x64), AMD64, IBM (Power PC), SUN (SPARC).

Question 4. What Are 1st/ 2nd/3rd/4th Generation Processors?

Answer :

The processors made of PMOS, NMOS, HMOS, HCMOS technology are called 1st/ 2nd/3rd/4th generation processor’s and are made up of 4, 8, 16, 32-bits.

Question 5. What Does Microprocessor Speed Depends On?

Answer :

The speed of microprocessor depends on various factors such as Data Bus Width (Number of instruction it processes) and clock speed.

Question 6. What Is Software And Hardware?

Answer :

The software is set of instruction or commands needed for performing a specific task by programmable device or a computing machine. The hardware refers to the component or device used to form computing machine in which software can be run and tested. Without software hardware is idle machine.

Question 7. Distinguish Between Microprocessor And Microcontroller?

Answer :

The microprocessor is a digital integrated circuit that can be programmed with a series of instructions to perform a specified function on data. The microcontroller is tiny little computer on single integrated circuit, which has memory, input-output on chip itself. So we can say microprocessor can perform few functions but microcontroller can perform many functions.

Question 8. What Are Disadvantages Of Microprocessor?

Answer :

Microprocessor has limitation on size of data. Most microprocessor does not support floating point operation.

Question 9. What Is The Difference Between Microprocessor And Microcontroller?

Answer :

In microprocessor more op-codes, few bit handling instructions but in microcontroller: fewer op-codes and more bit handling instructions also microcontroller defined as a device that includes microprocessor, memory and input-output signal lines in a single chip.

Question 10. What Is An Instruction?

Answer :

An instruction is an order given to a computer processor by a computer program. At the lowest level each instruction set is a sequence of 0s and 1s that describes a physical operation that computer is to perform (such as “Add”) and depending on the particular instruction type, the specification of special storage areas called registers that may contain data be used in carrying out the instruction or the location in computer memory of data.

Question 11. What Is Clock Cycle?

Answer :

The speed of computer processor is determined by clock cycle, which is amount of time between two pulses of an oscillator. In general, the higher number of pulses per second the faster the computer processor will be able to process information.

Question 12. What Is Instruction Cycle?

Answer :

The sequence of operation that the processor has to carry out while executing a instruction is called instruction cycle. Each instruction cycle of processor consist of a number of machine cycles. The sequence of stages is:

1. Read an instruction.
2. Decode the instruction.
3. Find the address of operand.
4. Retrieve an operand.
5. Perform desired operation.
6. Find the address of destination.
7. Store the result into destination.

Question 13. What Is Machine Cycle?

Answer :

The steps performed by computer processor for each machine language instruction received. The machine cycle is 4 process cycle.

• Fetch: Retrieve an instruction from memory
• Decode: Translate the retrieved instruction into series of computer commands.
• Execute: Execute the computer command.
• Store: Send and write the result back into memory.

Question 14. Explain The Function Of Cpu In Microprocessor?

Answer :

A Microprocessor controls all the functions of CPU Central Processing Unit of a computer or digital device. The microprocessor is programmed to give and receive instructions from other components of the device. The system can control everything from small devices such as calculators and mobile phones to large automobile.

Question 15. What Is Register?

Answer :

In computer architecture, a processor register (or general purpose register) is a small amount of storage available on the CPU whose contents can be accessed more quickly than storage available elsewhere. Typically, this specialized storage is not considered part of normal memory range for the machine. Processor registers are at the top of the memory hierarchy, and provide the fastest way for a CPU to access data.

Question 16. What Is Called Scratch Pad Of Computer?

Answer :

Cache memory is scratch pad of computer.

Question 17. Why Does Microprocessor Contain Rom Chip?

Answer :

Microprocessor contain ROM chip because it contain instruction to execute data.

Question 18. Why Status Signal Is Provided In Microprocessor?

Answer :

The status signal can be used by the system designer to track the internal operation of the processor. Also it can be used for memory expansion (by providing separate memory bank for program, data and selecting the bank using status signals.

Question 19. What Is Programmable Peripheral Device?

Answer :

If the function performed by a peripheral device can be altered or changed by a program instruction then the peripheral device is called programmable device. Usually the programmable devices will have control registers. The device can be programmed by sending control word in the prescribed format to the control register.

Question 20. Explain The Working Of A Handshake Output Port?

Answer :

In handshake output operation the processor will load a data to port. When the port receives the data, it will inform the output device to collect the data. Once the output device accepts the data, the port will inform the processor that it is empty. Now the processor can load another data to port and above process is repeated.

Question 21. What Is Cache Memory?

Answer :

Cache memory is small high speed memory. It is used for temporary storage of data & information between main memory and CPU (central processing unit).

Question 22. Define Hcmos?

Answer :

High density n-type Complementary Metal Oxide silicon field effect Transistor.

Question 23. What Is Flag?

Answer :

Flag is flip-flop used to store the information about the status of a processor and status of instruction executed most recently.

Question 24. What Is Nv-ram?

Answer :

Non Volatile Read Write memory, also called flash memory. It is also known as shadow RAM.

Question 25. What Is Direction Flag?

Answer :

This is used by string manipulation instructions. If this flag bit is ‘0’, the string is processed beginning from the lowest to highest address i.e. Auto increment mode. Otherwise string is processed from the highest towards the lowest address i.e. auto decrementing mode.

Question 26. What Is Instruction Set?

Answer :

The set of instructions that the microprocessor can execute.

Question 27. Why Address Bus Is Unidirectional?

Answer :

The address is identification number used by the microprocessor to identify or access a memory location or IO device. It is an output signal from the processor. Hence the address bus is unidirectional.

Here is the end of this post. Probably in the next post will see more challenging interview questions on embedded processors. I hope you’ll find this post educational.