VTU Viva Questions With Answers

I am preparing for viva of B.E Computer Science Engineering of Visvesvaraya Technological University VTU so can you please tell me some general viva questions?

[pawan]

Ok, here I am telling you some questions generally ask in the viva of B.E Computer Science Engineering.

B.E Computer Science Engineering viva questions

1) What is MicroProcessor?
A:- A MicroProcessor is a multipurpose, programmable, clock-driven, register-based electronic device that reads binary instructions from a storage device called memory, accepts binary data as input and processes the data according to those instruction, and provides results as output.

2) What are the different types of Addressing Modes?
A: - There are 12 different types of Addressing Modes. They are:-
<1> Immediate:-The Immediate data is a part of instruction, and appears in the form of successive bytes.

<2> Direct:-A 16-bit memory address (offset) is directly specified in the instruction as a part of it.

<3> Register:-Data is stored in a register and it is referred using the particular register (except IP).

<4> Register Indirect:-The address of the memory location which contains data or operand is determined in an indirect way.

<5> Indexed:-offset of the operand is stored in one of the index registers.

<6> Register Relative:-The data is available at an effective address formed by adding an 8-bit or 16-bit displacement with the content of any one of the registers BX,BP,SI and DI in the default (either DS or ES) segment.

<7> Based Indexed:-The effective address of the data is formed, in this addressing mode, by adding content of a base register to the content of an index register.

<8> Relative Based Indexed:- The effective address is formed by adding an 8 or 16-bit displacement with the sum of contents of any one of the base registers and any one of the index registers, in the default segment.

<9> Intrasegment Direct Mode:-In this mode, the address to which the control is to be transferred lies in the segment in which the control transfer instruction lies and appears directly in the instruction as an immediate displacement value.

<10> Intrasegment Indirect Mode:-In this mode, the displacement to which the control is to be transferred, is in the same segment in which the control transfer instruction lies, but it is passed to the instruction indirectly.

<11> Intersegment Direct:-In this mode, the address to which the control is to be transferred is in a different segment.

<12> Intersegment Indirect:-In this mode, the address to which the control is to be transferred lies in a different segment and it is passed to the instruction indirectly sequentially.

3) What are the General Data Registers & their uses?
A: - The Registers AX, BX, CX, DX are the general Purpose 16-bit registers. AX register as 16-bit accumulator. BX register is used as an offset Storage. CX register is used as default or implied counter. DX register is used as an implicit operand or destination in case of a few instructions.

4) What are Segment Registers & their uses?
A:-There are 4 Segment Registers Code Segment (CS), Data Segment (DS), Extra Segment (ES) & Stack Segment (SS) registers. CS is used for addressing memory location in code. DS is used to points the data. ES refers to a segment which is essentially in another data segment. SS is used for addressing stack segment of memory.

5) What are Flag registers?
A:-Divided into 2 parts:-Condition code or status flags and machine control flags.
S -Sign Flag:-Is to set when the result of any computation is negative.
Z -Zero Flag:-Is to set if the result of the computation or comparision performed by the previous instruction is zero.
C -Carry Flag:-Is set when there is carry out of MSB in case of addition or a borrow in case of subtraction.
T -Trap Flag:-Is set, the processor enters the single step execution mode.
I -Interrupt Flag:-Is set, the mask able interrupts are recognized by the CPU.
D -Direction Flag:-Is set for Auto incrementing or Auto decrementing mode in string manipulation instructions.
AC -Auxiliary Carry Flag:-Is set if there is a carry from the lowest nibble during addition or borrow for the lowest nibble.
O -Overflow Flag:-Is set if the result of a signed operation is large enough to be accommodated in a destination register.

6) What does the 8086 Architecture contain?
A:-The complete architecture of 8086 can be divided into 2types:-Bus Interface Unit (BIU) & Execution Unit.
The BIU contains the circuit for physical address calculations and a pre coding instruction byte queue & it makes the bus signals available for external interfacing of the devices.
The EU contains the register set of 8086 except segment registers and IP. It has a 16-bit ALU, able to perform arithmetic and Logic operations.

7) What are Data Copy/Transfer Instructions?
A: - Mov
Push
Pop
Xchg
In
Out
Xlat
Lea
Lds/Les
Lahf
Sahf
Pushf
Popf

8) What are Machine Control Instructions?
A: - Nop
Hlt
Wait
Lock

9) What are Flag Manipulation Instructions?
A: - Cld
Std
Cli
Sti

10) What are String Instructions?
A: - Rep
MovSB/MovSW
Cmps
Scas
Lods
Stos