These interview questions test the knowledge of x86 Intel architecture and 8086 microprocessor specifically.
- What is a Microprocessor? - Microprocessor is a program-controlled device, which fetches the instructions from memory, decodes and executes the instructions. Most Micro Processor are single- chip devices.
- Give examples for 8 / 16 / 32 bit Microprocessor? - 8-bit Processor - 8085 / Z80 / 6800; 16-bit Processor - 8086 / 68000 / Z8000; 32-bit Processor - 80386 / 80486.
- Why 8085 processor is called an 8 bit processor? - Because 8085 processor has 8 bit ALU (Arithmetic Logic Review). Similarly 8086 processor has 16 bit ALU.
- What is 1st / 2nd / 3rd / 4th generation processor? - The processor made of PMOS / NMOS / HMOS / HCMOS technology is called 1st / 2nd / 3rd / 4th generation processor, and it is made up of 4 / 8 / 16 / 32 bits.
- Define HCMOS? - High-density n- type Complimentary Metal Oxide Silicon field effect transistor.
- What does microprocessor speed depend on? - The processing speed depends on DATA BUS WIDTH.
- Is the address bus unidirectional? - The address bus is unidirectional because the address information is always given by the Micro Processor to address a memory location of an input / output devices.
- Is the data bus is Bi-directional? - The data bus is Bi-directional because the same bus is used for transfer of data between Micro Processor and memory or input / output devices in both the direction.
- What is the disadvantage of microprocessor? - It has limitations on the size of data. Most Microprocessor does not support floating-point operations.
- What is the difference between microprocessor and microcontroller? - In Microprocessor more op-codes, few bit handling instructions. But in Microcontroller: fewer op-codes, more bit handling Instructions, and also it is defined as a device that includes micro processor, memory, & input / output signal lines on a single chip.
- What is meant by LATCH? - Latch is a D- type flip-flop used as a temporary storage device controlled by a timing signal, which can store 0 or 1. The primary function of a Latch is data storage. It is used in output devices such as LED, to hold the data for display.
- Why does microprocessor contain ROM chips? - Microprocessor contain ROM chip because it contain instructions to execute data.
- What is the difference between primary & secondary storage device? - In primary storage device the storage capacity is limited. It has a volatile memory. In secondary storage device the storage capacity is larger. It is a nonvolatile memory. Primary devices are: RAM / ROM. Secondary devices are: Floppy disc / Hard disk.
- Difference between static and dynamic RAM? - Static RAM: No refreshing, 6 to 8 MOS transistors are required to form one memory cell, Information stored as voltage level in a flip flop. Dynamic RAM: Refreshed periodically, 3 to 4 transistors are required to form one memory cell, Information is stored as a charge in the gate to substrate capacitance.
- What is interrupt? - Interrupt is a signal send by external device to the processor so as to request the processor to perform a particular work.
- What is cache memory? - Cache memory is a small high-speed memory. It is used for temporary storage of data & information between the main memory and the CPU (center processing unit). The cache memory is only in RAM.
- What is called “Scratch pad of computer� - Cache Memory is scratch pad of computer.
- Which transistor is used in each cell of EPROM? - Floating –gate Avalanche Injection MOS (FAMOS) transistor is used in each cell of EPROM.
- Differentiate between RAM and ROM? - RAM: Read / Write memory, High Speed, Volatile Memory. ROM: Read only memory, Low Speed, Non Voliate Memory.
- What is a compiler? - Compiler is used to translate the high-level language program into machine code at a time. It doesn’t require special instruction to store in a memory, it stores automatically. The Execution time is less compared to Interpreter.
- Which processor structure is pipelined? - All x86 processors have pipelined structure.
- What is flag? - Flag is a flip-flop used to store the information about the status of a processor and the status of the instruction executed most recently
- What is stack? - Stack is a portion of RAM used for saving the content of Program Counter and general purpose registers.
- Can ROM be used as stack? - ROM cannot be used as stack because it is not possible to write to ROM.
- What is NV-RAM? - Nonvolatile Read Write Memory, also called Flash memory. It is also know as shadow RAM.
20 Comments on x86 interview questions and answers
THE ANSWER TO THE THRID QUESTION DOES NOT SEEM CORRECT.
8085 HAS AN 8 BIT ADDRESS BUS AND 8086 HAS 16 BIT ADDRESS BUS. THAT IS WHY THEY ARE CALLED AS 8 AND 16 BIT PROCESSORS RESPECTIVELY.
THE ANSWER TO THE THIRD QUESTION IS CORRECT
micro processors are not classified based on the address pins but on the amount of data that it can read at a time and process.
the answer to the 3rd Q is right. 8086 has 20 bit address bus and 8085 has 16bit address bus. 8085 can process 8bit data and 8086 can process 16bit data.
ans to ques no. 6
What does microprocessor speed depend on? - The processing speed depends on DATA BUS WIDTH
seems to be in perfect as the speed of a microprocessor also depends on its clock speed.
Please i have some problem solving this:
Q1: Differentiate between A PROGRAM INPUT/OUTPUT INTERRUPTS INTERVALS
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Hi, I want to know the differences between 16-bit architecture & 32-bit architecture immedietly.I am waiting online. please give me the answer as early as possible.
Speed of a digital circuit depends on many parameters: netlist synthesis, placement and routing in a layout-to-be-taped out, pipelining (if at all) in the critical path of the circuit, and the data bus width. So, answer to Q.6 is not wrong but only a part of correct answer.
Most important, it’s not the clock frequency that defines the speed of the circuit, but speed of the circuit that defines clock frequency(understand limitations imposed by set-up time, hold time, etc).
Ans 2 d 3rd questin is
8085 has 8 bit data bus,so at a time 8085 can process 8 bits of data
And 8086 has 16 bit data bus,so at a time 8085 can process 16 bits of data
and nt called becos dey hav address pins or alu
The answer for the 3rd Question is the size of ALU register. Think of an architecture with 16-bit data bus but 8-bit ALU. The processor will obviously process each 8-bit and not 16-bit!
for Q number 6, its the speed of the crystal clock and decrease in the number of operations that are required to execute each instruction. true the layout and all matters but then a processor running at 60MHz would run after all the calculation of the delays..
have fun!
answer by srinivas is wrong. the answer is that the 8085 has 8 bit data bus and the 8086 has 16 bit data bus which is why they are known as 8 bit and 16 bit processors. they are classified on the basis of data bus and not on address bus. ok
Answer to Q-3 is correct. A Processor can be classified either on basis of data bus size or ALU data handling capability.
Answer to the 3rd question is partially correct.
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Bit size of a processor depends on ALU, Data Bus and Address Bus
sizes. One among the smallest is taken as CPU bit size.
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i want the relation in 8086(micro processor) between hexa decimal values of letters and numbers and comma and every thing please help to me to send the answer in mail thank you
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answer to Q11 is wrong.
Both latches and flip-flops are circuit elements whose output depends not only on the current inputs, but also on previous inputs and outputs. The difference between a latch and a flip-flop is that a latch does not have a clock signal, whereas a flip-flop always does. so a flip flop can be made using a latch but vice versa is not possible. latches are built from logic gates.
Also, you can say that a latch is level triggered while the flip flop is edge triggered.
however for very high digital circuits flip flop may contain much more than latches for ex comparator, sample & hold circuitry etc.
answer to Q13 is partialy incorrect.
primary memory has limited storage capacity but primary memory as a whole is not volatile. only a part of it i.e. RAM is volatile. ROM is non volatile. infact ROM contains the initial instructions like boot strap loader & operating system which have to be loaded into microprocessor when power is turned on. RAM is used for storing data to be processed & provides this data to cache memory during processing. after processing previous data, contents of RAM has to be wiped off to accomodate next data therefore it is kept volatile.
add on to Q15
interrupt necessarily need not be an external signal to execute some work. interrupt can also be generated internaly(i.e. within the processor) by watch dog timer in case of improper working of the processor. theese conditions include hanged or deadlock state of the processor due to execution of some particular part of instruction. interrupt generated by watch dog timer usualy resets the complete processor to bring it into its initial state.
WHAT IS LATCH,CACHE MEMORY.FUNCTIONS AND DIFFERENCIES BETWEEN CACHE AND LATCHE MEMORY
q.no. 16 is at last sort of confusing.
if we use more than one level of cache then L1 is used within the CPU and L2 is uesd outside of the processor.Material may be used as static Ram in both cases. So, cache is never used in RAM.
8086 is works on a 5v dc.it is 40 pin DIP.it’s clock frequency from 2mhz to 8mhz.it has 20bit adress line.so it can access 2^20 =1 mb memory location.it is a 16 bit processor,ie it can tranfer 16 bit data at a time.
which microprocessor is used in television?
advantages of using microprocessor in television?
work of micrprocessor in television?