IT Interview Questions

1. Which is the tool used to connect the user and the computer? - Interpreter is the tool used to connect the user and the tool.
2. What is the position of the Stack Pointer after the PUSH instruction? - The address line is 02 less than the earlier value.
3. What is the position of the Stack Pointer after the POP instruction? - The address line is 02 greater than the earlier value.
4. Logic calculations are done in which type of registers? - Accumulator is the register in which Arithmetic and Logic calculations are done.

1. What are the various registers in 8085? -
   Accumulator register, Temporary register, Instruction register, Stack Pointer, Program Counter are the various registers in 8085 .
2. In 8085 name the 16 bit registers? -
   Stack pointer and Program counter all have 16 bits.
3. What are the various flags used in 8085? -
   Sign flag, Zero flag, Auxillary flag, Parity flag, Carry flag.
4. What is Stack Pointer? -
   Stack pointer is a special purpose 16-bit register in the Microprocessor, which holds the address of the top of the stack.

1. What are Software interrupts? -
   RST0, RST1, RST2, RST3, RST4, RST5, RST6, RST7.
2. Which interrupt has the highest priority? -
   TRAP has the highest priority.
3. Name 5 different addressing modes? -
   Immediate, Direct, Register, Register indirect, Implied addressing modes.
4. How many interrupts are there in 8085? -
   There are 12 interrupts in 8085.
5. What is clock frequency for 8085? -
   3 MHz is the maximum clock frequency for 8085.
6. What is the RST for the TRAP? -
   RST 4.5 is called as TRAP.

1. Have you studied buses? What types?
2. Have you studied pipelining? List the 5 stages of a 5 stage pipeline. Assuming 1 clock per stage, what is the latency of an instruction in a 5 stage machine? What is the throughput of this machine ?
3. How many bit combinations are there in a byte?
4. For a single computer processor computer system, what is the purpose of a processor cache and describe its operation?
5. Explain the operation considering a two processor computer system with a cache for each processor.
6. What are the main issues associated with multiprocessor caches and how might you solve them?

1. A 2MB PCM(pulse code modulation) has…

a) 32 channels
b) 30 voice channels & 1 signaling channel.
c) 31 voice channels & 1 signaling channel.
d) 32 channels out of which 30 voice channels, 1 signaling channel, & 1 synchronization channel.

Ans: c

2. Time taken for 1 satellite hop in voice communication is…

a) 1/2 second
b) 1 seconds
c) 4 seconds
d) 2 seconds

Ans: (a)

3. Max number of satellite hops allowed in voice communication is:

a) only one
b) more han one
c) two hops
d) four hops