Microprocessor Interview Questions and Answers
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.
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.
Why crystal is a preferred
Because of high stability, large Q (Quality Factor) & the frequency that doesn’t
drift with aging. Crystal is used as a clock source most of the times.
In 8085 which is called as
High order / Low order Register?
Flag is called as Low order register & Accumulator is called as High order
What is Tri-state logic?
Three Logic Levels are used and they are High, Low, High impedance state. The
high and low are normal logic levels & high impedance state is electrical open
circuit conditions. Tri-state logic has a third line called enable line.
What happens when HLT
instruction is executed in processor?
The Micro Processor enters into Halt-State and the buses are tri-stated.
Which Stack is used in 8085?
LIFO (Last In First Out) stack is used in 8085.In this type of Stack the last
stored information can be retrieved first
What is Program counter?
Program counter holds the address of either the first byte of the next
instruction to be fetched for execution or the address of the next byte of a
multi byte instruction, which has not been completely fetched. In both the cases
it gets incremented automatically one by one as the instruction bytes get
fetched. Also Program register keeps the address of the next instruction.
What are the various
registers in 8085?
Accumulator register, Temporary register, Instruction register, Stack Pointer,
Program Counter are the various registers in 8085
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.
Name the processor lines of
two major manufacturers?
High-end: Intel - Pentium (II, III, 4), AMD - Athlon. Low-end: Intel - Celeron,
AMD - Duron. 64-bit: Intel - Itanium 2, AMD - Opteron.
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