1) How many bit 8086 microprocessor is?
2) What is the size of data bus of 8086?
3) What is the size of address bus of 8086?
4) What is the max memory addressing capacity of 8086?
5) Which are the basic parts of 8086?
6) What are the functions of BIU?
7) What are the functions of EU?
8) How many pin IC 8086 is?
9) What IC8086 is?
10) What is the size of instruction queue in 8086?
11) What is the size of instruction queue in 8088?
12) Which are the registers present in 8086?
13) What do you mean by pipelining in 8086?
14) How many 16 bit registers are available in 8086?
15) Specify addressing modes for any instruction?
16) What do you mean by assembler directives?
17) What .model small stands for?
18) What is the supply requirement of 8086?
19) What is the relation between 8086 processor frequency & crystal
20) Functions of Accumulator or AX register?
21) Functions of BX register?
22) Functions of CX register?
23) Functions of DX register?
24) How Physical address is generated?
25) Which are pointers present in this 8086?
26) Which is by default pointer for CS/ES?
27) How many segments present in it?
28) What is the size of each segment?
29) Basic difference between 8085 and 8086?
30) Which operations are not available in 8085?
# What are the flags in 8086? - In 8086 Carry flag, Parity flag, Auxiliary carry flag, Zero flag, Overflow flag, Trace flag, Interrupt flag, Direction flag, and Sign flag.
# What are the various interrupts in 8086? - Maskable interrupts, Non-Maskable interrupts.
# What is meant by Maskable interrupts? - An interrupt that can be turned off by the programmer is known as Maskable interrupt.
# What is Non-Maskable interrupts? - An interrupt which can be never be turned off (ie.disabled) is known as Non-Maskable interrupt.
# Which interrupts are generally used for critical events? - Non-Maskable interrupts are used in critical events. Such as Power failure, Emergency, Shut off etc.,
# Give examples for Maskable interrupts? - RST 7.5, RST6.5, RST5.5 are Maskable interrupts
# Give example for Non-Maskable interrupts? - Trap is known as Non-Maskable interrupts, which is used in emergency condition.
# What is the Maximum clock frequency in 8086? - 5 Mhz is the Maximum clock frequency in 8086.
# What are the various segment registers in 8086? - Code, Data, Stack, Extra Segment registers in 8086.
# Which Stack is used in 8086? - FIFO (First In First Out) stack is used in 8086.In this type of Stack the first stored information is retrieved first.
# What are the address lines for the software interrupts? -
RST 0 0000 H
RST1 0008 H
RST2 0010 H
RST3 0018 H
RST4 0020 H
RST5 0028 H
RST6 0030 H
RST7 0038 H
# What is SIM and RIM instructions? - SIM is Set Interrupt Mask. Used to mask the hardware interrupts. RIM is Read Interrupt Mask. Used to check whether the interrupt is Masked or not.
# Which is the tool used to connect the user and the computer? - Interpreter is the tool used to connect the user and the tool.
# What is the position of the Stack Pointer after the PUSH instruction? - The address line is 02 less than the earlier value.
# What is the position of the Stack Pointer after the POP instruction? - The address line is 02 greater than the earlier value.
# Logic calculations are done in which type of registers? - Accumulator is the register in which Arithmetic and Logic calculations are done.
# What are the different functional units in 8086? - Bus Interface Unit and Execution unit, are the two different functional units in 8086.
# Give examples for Micro controller? - Z80, Intel MSC51 &96, Motorola are the best examples of Microcontroller.
# What is meant by cross-compiler? - A program runs on one machine and executes on another is called as cross-compiler.
# What are the address lines for the hardware interrupts? -
RST 7.5 003C H
RST 6.5 0034 H
RST 5.5 002C H
TRAP 0024 H
# Which Segment is used to store interrupt and subroutine return address registers? - Stack Segment in segment register is used to store interrupt and subroutine return address registers.
# Which Flags can be set or reset by the programmer and also used to control the operation of the processor? - Trace Flag, Interrupt Flag, Direction Flag.
# What does EU do? - Execution Unit receives program instruction codes and data from BIU, executes these instructions and store the result in general registers.
# Which microprocessor accepts the program written for 8086 without any changes? - 8088 is that processor.
# What is the difference between 8086 and 8088? - The BIU in 8088 is 8-bit data bus & 16- bit in 8086.Instruction queue is 4 byte long in 8088and 6 byte in 8086.
31) What is the difference between min mode and max mode of 8086?
32) What is the difference between near and far procedure?
33) What is the difference between Macro and procedure?
34) What is the difference between instructions RET & IRET?
35) What is the difference between instructions MUL & IMUL?
36) What is the difference between instructions DIV & IDIV?
37) What is difference between shifts and rotate instructions?
38) Which are strings related instructions?
39) Which are addressing modes and their examples in 8086?
40) What does u mean by directives?
41) What does u mean by Prefix?
42) What .model small means?
43) Difference between small, medium, tiny, huge?
44) What is dd, dw, db?
45) Interrupts in 8086 and there function.
46) What is the function of 01h of Int 21h?
47) What is the function of 02h of Int 21h?
48) What is the function of 09h of Int 21h?
49) What is the function of 0Ah of Int 21h?
50) What is the function of 4ch of Int 21h?
51) What is the reset address of 8086?
52) What is the size of flag register in 8086? Explain all.
53) What is the difference between 08H and 01H functions of INT 21H?
54) Which is faster- Reading word size data whose starting address is at
even or at odd address of memory in 8086?
55) Which are the default segment base: offset pairs?
56) Can we use SP as offset address holder with CS?
57) Which are the base registers in 8086?
58) Which is the index registers in 8086?
59) What do you mean by segment override prefix?
60) Whether micro reduces memory requirements?
61) What do you mean by macro?
62) What is diff between macro and procedure?
63) Types of procedure?
64) What TASM is?
65) What TLINK is?
66) What TD is?
67) What do u mean by assembler?
68) What do u mean by linker?
69) What do u mean by loader?
70) What do u mean by compiler?
71) What do u mean by emulator?
72) Stack related instruction?
73) .stack 100 means?
74) What do you mean by 20 dup (0)?
75) Which flags of 8086 are not present in 8085?
76) What is the size of flag register?
77) Can you perform 32 bit operation with 8086? How?
78) Whether 8086 is compatible with Pentium processor?
79) What is 8087? How it is different from 8086?
80) While accepting no. from user why u need to subtract 30 from that?
81) While displaying no. from user why u need to add 30 to that?
82) What are ASCII codes for nos. 0 to F?
83) How does U differentiate between positive and negative numbers?
84) What is range for these numbers?
85) Which no. representation system you have used?
86) What is LEA?
87) What is @data indicates in instruction- MOV ax, @data?
88) What is maximum size of the instruction in 8086?
89) Why we indicate FF as 0FF in program?
90) What is mul BX and div BX? Where result goes?
91) Where queue is present?
92) What is the advantage of using internal registers?
93) What is SI, DI and their functions?
94) Which are the pointers used in 8086 and their functions?
95) What is a type of queue in 8086?
96) What is minimum mode of 8086?
97) What is maximum mode of 8086?
98) Which are string instructions?
99) In string operations which is by default string source pointer?
100) In string operations which is by default string destination pointer?
1) What do you mean by assembler?
2) What do you mean by linker?
3) What do you mean by debugger?
4) What do you mean by compiler?
5) What do you mean by locator?
6) What do you mean by emulator?
7) When divide overflow error occurs?
8) What .startup stands for?
9) Explain the logic of array addition program.
10) Explain the logic of finding out negative nos. from an array of signed
11) Explain the logic of code conversion (BCD to hex and hex to BCD)
12) Explain the logic of multiplication (by successive addition and shift and
add method) program.
13) Explain the logic of non overlap and overlap block transfer program
14) Explain the logic of string related programs.
15) Which assembler directives are used with near procedure?
16) Which assembler directives are used with far procedure?
1) What IC 80386 is?
2) How many pin IC 80836 is?
3) 80386 is how many bit processor?
4) What is the size of instruction queue in 80386?
1) What do you mean by interrupt?
2) Which are the hardware and software interrupts in 8086?
3) Mention the priority of interrupts in8086.
4) What is int1, int2, int3?
5) What do you mean by NMI interrupt?
6) What do you mean by IVT in 8086?
7) What is the size of IVT?
8) Where IVT is located?
9) Which steps 8086 follows to handle any interrupt?
1) What are the types of interfacing?
2) Compare memory interfacing and IO interfacing.
3) What are the types of IO interfacing?
4) What is the difference between direct and indirect IO interfacing?
5) What is the difference between memory mapped IO and IO mapped IO
8255 (programmable peripheral interface) :
1) What IC 8255 is?
2) How many pin IC 8255 is?
3) Explain control word format of 82
1) what is segmentation?
2) how many bit processor does 8086?
3) how many address lines in 8086
4) how many data lines in 8086?
5) multiplexed lines in 8086?
6) over flow flag, interrupt flag ,direction flag, trap flag?
7) role of pointers ?
8) how 16 bit processor generates 20 bit addresses
9) instructions set of 8086
10) timing diagram of 8086
11) min/max mode working of 8086?
12) pin difference in min/max mode
13) interrupt structure in 8086?
14) how an interrupt is acknowledged?
15) how the cs:ip is working during interrupt
16) new cs:ip during interrupt
17) how the even odd address are assigned through 8086?
These interview questions test the knowledge of x86 Intel architecture and 8086 microprocessor specifically.
1. 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.
2. 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.
3. 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.
4. 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.
5. Define HCMOS? - High-density n- type Complimentary Metal Oxide Silicon field effect transistor.
6. What does microprocessor speed depend on? - The processing speed depends on DATA BUS WIDTH.
7. 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.
8. 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.
9. What is the disadvantage of microprocessor? - It has limitations on the size of data. Most Microprocessor does not support floating-point operations.
10. 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.
11. 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.
12. Why does microprocessor contain ROM chips? - Microprocessor contain ROM chip because it contain instructions to execute data.
13. 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.
14. 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.
15. 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.
16. 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.
17. What is called .Scratch pad of computer.? - Cache Memory is scratch pad of computer.
18. Which transistor is used in each cell of EPROM? - Floating .gate Avalanche Injection MOS (FAMOS) transistor is used in each cell of EPROM.
19. Differentiate between RAM and ROM? - RAM: Read / Write memory, High Speed, Volatile Memory. ROM: Read only memory, Low Speed, Non Voliate Memory.
20. 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.
21. Which processor structure is pipelined? - All x86 processors have pipelined structure.
22. 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
23. What is stack? - Stack is a portion of RAM used for saving the content of Program Counter and general purpose registers.
24. Can ROM be used as stack? - ROM cannot be used as stack because it is not possible to write to ROM.
25. What is NV-RAM? - Nonvolatile Read Write Memory, also called Flash memory. It is also know as shadow RAM.