Give examples for Micro controller?
Z80, Intel MSC51 &96, Motorola are the best examples of Microcontroller.
What is clock frequency for 8085?
3 MHz is the maximum clock frequency for 8085.
Give an example of one address microprocessor?
8085 is a one address microprocessor.
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
What is meant by a bus?
A bus is a group of conducting lines that carriers data, address, & control signals.
What are the various registers in 8085?
Accumulator register, Temporary register, Instruction register, Stack Pointer, Program Counter are the various registers in 8085
Why crystal is a preferred clock source?
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 Register.
Name 5 different addressing modes?
Immediate, Direct, Register, Register indirect, Implied addressing modes
In what way interrupts are classified in 8085?
In 8085 the interrupts are classified as Hardware and Software interrupts.
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.
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 is the RST for the TRAP?
RST 4.5 is called as TRAP.
What are level-triggering interrupt?
RST 6.5 & RST 5.5 are level-triggering interrupts.
Monday, March 16, 2009
Microprocessors Interview Questions of Part -----9
Where does CPU Enhanced mode originate from?
Intel’s 80386 was the first 32-bit processor, and since the company had to backward-support the 8086. All the modern Intel-based processors run in the Enhanced mode, capable of switching between Real mode (just like the real 8086) and Protected mode, which is the current mode of operation.
How many bit combinations are there in a byte?
Byte contains 8 combinations of bits.
Have you studied buses? What types?
There are three types of buses.
Address bus: This is used to carry the Address to the memory to fetch either Instruction or Data.
Data bus : This is used to carry the Data from the memory.
Control bus : This is used to carry the Control signals like RD/WR, Select etc.
What is the Maximum clock frequency in 8086?
5 Mhz is the Maximum clock frequency in 8086.
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
What is Non-Maskable interrupts?
An interrupt which can be never be turned off (ie.disabled) is known as Non-Maskable interrupt
What are the different functional units in 8086?
Bus Interface Unit and Execution unit, are the two different functional units in 8086.
What are the various segment registers in 8086?
Code, Data, Stack, Extra Segment registers in 8086.
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 StacWhich Stack is used in 8086? k 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 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 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.
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.
Give example for Non-Maskable interrupts?
Trap is known as Non-Maskable interrupts, which is used in emergency condition.
Intel’s 80386 was the first 32-bit processor, and since the company had to backward-support the 8086. All the modern Intel-based processors run in the Enhanced mode, capable of switching between Real mode (just like the real 8086) and Protected mode, which is the current mode of operation.
How many bit combinations are there in a byte?
Byte contains 8 combinations of bits.
Have you studied buses? What types?
There are three types of buses.
Address bus: This is used to carry the Address to the memory to fetch either Instruction or Data.
Data bus : This is used to carry the Data from the memory.
Control bus : This is used to carry the Control signals like RD/WR, Select etc.
What is the Maximum clock frequency in 8086?
5 Mhz is the Maximum clock frequency in 8086.
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
What is Non-Maskable interrupts?
An interrupt which can be never be turned off (ie.disabled) is known as Non-Maskable interrupt
What are the different functional units in 8086?
Bus Interface Unit and Execution unit, are the two different functional units in 8086.
What are the various segment registers in 8086?
Code, Data, Stack, Extra Segment registers in 8086.
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 StacWhich Stack is used in 8086? k 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 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 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.
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.
Give example for Non-Maskable interrupts?
Trap is known as Non-Maskable interrupts, which is used in emergency condition.
Wednesday, March 11, 2009
Microprocessors Interview Questions part ---8
Write the uses of microprocessors in Medical Instrumentation field?
Patient Monitoring in Intensive Care Unit, Pathological Analysis and the measurement of parameters like blood pressure and temperature.
Tell me about a problem you had with a supervisor
Biggest trap of all. This is a test to see if you will speak ill of your boss. If you fall for it and tell about a problem with a former boss, you may well below the interview right there. Stay positive and develop a poor memory about any trouble with a supervisor.
Have you consider starting your own business?
Again it’s best to:
Gauge this company’s corporate culture before answering and…
Be honest (which doesn’t mean you have to vividly share your fantasy of the franchise or bed-and-breakfast you someday plan to open).
In general, if the corporate culture is that of a large, formal, military-style structure, minimize any indication that you’d love to have your own business. You might say, “Oh, I may have given it a thought once or twice, but my whole career has been in larger organizations. That’s where I have excelled and where I want to be.”
If the corporate culture is closer to the free-wheeling, everybody’s-a-deal-maker variety, then emphasize that in a firm like this, you can virtually get the best of all worlds, the excitement of seeing your own ideas and plans take shape…combined with the resources and stability of a well-established organization. Sounds like the perfect environment to you.
In any case, no matter what the corporate culture, be sure to indicate that any desires about running your own show are part of your past, not your present or future.
The last thing you want to project is an image of either a dreamer who failed and is now settling for the corporate cocoon…or the restless maverick who will fly out the door with key accounts, contacts and trade secrets under his arms just as soon as his bankroll has gotten rebuilt.
Always remember: Match what you want with what the position offers. The more information you’ve uncovered about the position, the more believable you can make your case
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 clock source?
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 Register.
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.
What’s the speed and device maximum specs for Firewire?
IEEE 1394 (Firewire) supports the maximum of 63 connected devices with speeds up to 400 Mbps. Where’s MBR located on the disk? Main Boot Record is located in sector 0, track 0, head 0, cylinder 0 of the primary active partition.
Patient Monitoring in Intensive Care Unit, Pathological Analysis and the measurement of parameters like blood pressure and temperature.
Tell me about a problem you had with a supervisor
Biggest trap of all. This is a test to see if you will speak ill of your boss. If you fall for it and tell about a problem with a former boss, you may well below the interview right there. Stay positive and develop a poor memory about any trouble with a supervisor.
Have you consider starting your own business?
Again it’s best to:
Gauge this company’s corporate culture before answering and…
Be honest (which doesn’t mean you have to vividly share your fantasy of the franchise or bed-and-breakfast you someday plan to open).
In general, if the corporate culture is that of a large, formal, military-style structure, minimize any indication that you’d love to have your own business. You might say, “Oh, I may have given it a thought once or twice, but my whole career has been in larger organizations. That’s where I have excelled and where I want to be.”
If the corporate culture is closer to the free-wheeling, everybody’s-a-deal-maker variety, then emphasize that in a firm like this, you can virtually get the best of all worlds, the excitement of seeing your own ideas and plans take shape…combined with the resources and stability of a well-established organization. Sounds like the perfect environment to you.
In any case, no matter what the corporate culture, be sure to indicate that any desires about running your own show are part of your past, not your present or future.
The last thing you want to project is an image of either a dreamer who failed and is now settling for the corporate cocoon…or the restless maverick who will fly out the door with key accounts, contacts and trade secrets under his arms just as soon as his bankroll has gotten rebuilt.
Always remember: Match what you want with what the position offers. The more information you’ve uncovered about the position, the more believable you can make your case
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 clock source?
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 Register.
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.
What’s the speed and device maximum specs for Firewire?
IEEE 1394 (Firewire) supports the maximum of 63 connected devices with speeds up to 400 Mbps. Where’s MBR located on the disk? Main Boot Record is located in sector 0, track 0, head 0, cylinder 0 of the primary active partition.
Microprocessors Interview Questions part --7
List the functions of Bus Interface Unit in 8086.
Sends out addressesFetches instructions from memoryReads data from ports and memoryWrites data to port and memory
List the branch related addressing mode:
Intra segment DirectIntra segment IndirectInter segment DirectInter Segment Indirect
Define Relative based indexed addressing mode:
Relative Based Indexed Addressing Mode : Effective Address is calculated by the sum of 8- or 16 bit displacement and a based indexed address.
E.A.= (BX or BP) + (SI or DI) +( 8 bit displacement (sign extended ) or 16 bit displacement)
Physical Address= E.A + (DS)*1610
Define Direct Addressing
A 16 bit offset address of the data memory location is specified with reference to the DS segment starting address.For.E.g MOV [1020H],5020H instruction transfers a word 5020H to the data memory location at 11020H if DS=1000H.
Define Immediate Addressing.
An 8 bit or 16 bit immediate data follows the instruction. For e.g MOV AX,5020H instruction transfers a word 5020H to the AX register .
Define Register Relative Addressing Mode.
Register Relative Addressing Mode : The Effective Address is Calculated by the sum of 8- or 16 bit displacement and the contents of a base Register or an index Register.
E.A. = content of(BX or BP or SI or DI) + (8 bit displacement (sign extended ) or 16 bit displacement
Physical Address = E.A +(DS)*1610
Compare the 8 bit microprocessors 8080A and 8085.
8080A is the predecessor of 8085. 8085 has the instruction set of 8080A plus some additional ones. Program written for 8080A will be executed by 8085. 8085 and 8080A are not pin compatible. Both require a +5V power supply
What are the limitations of 8085 MPU?
(i) The lower order address bus of the 8085 microprocessor is multiplexed (time shared) with the data bus. The buses need to be demultiplexed.
(ii) Appropriate control signals need to be generated to interface memory and I/O with the 8085.
Write about RST pins in 8085?
In 8085 ,three RST pins are available, such as RST 7.5 ,RST 6.5 , RST 5.5
RST represents Restart Interrupts. These are vectored interrupts that transfer the program control to specific memory locations. They have higher priorities than the INTR interrupt. Among these three, the priority order is 7.5,6.5,5.5.
List the four operations commonly performed by MPU( Micro processing Unit)?
Memory Read : Reads data (or instructions) from memory.Memory Write: Writes Data (or instructions) into memory.I/O Read: Accepts data from input devices
.I/O Write: Sends data to output devices
What is compiler?
Compiler is a program that translates English like words of a high level language into the machine language of a computer. A compiler read a given program ,called a source code, in its entirely and then translates the program into the machine language, which is called an Object Code.
What do you mean ‘ Data Width’?
Data Width is the width of the ALU. An 8 bit ALU can add / subtract/ multiply etc.. two 8 bit numbers . In many cases, the external data bus is the same width as the ALU, but not always. The 8088 had a 16 bit ALU and 8 bit bus , while the modern
List the limitations of 8 bit microprocessor:
Lower Execution Speed
It can address less memory size
Few instructions are available
Define Real Time
Real Time Systems are those in which timeliness is as important as the correctness of the outputs, although this does not mean that they have to be “fast systems”.
Sends out addressesFetches instructions from memoryReads data from ports and memoryWrites data to port and memory
List the branch related addressing mode:
Intra segment DirectIntra segment IndirectInter segment DirectInter Segment Indirect
Define Relative based indexed addressing mode:
Relative Based Indexed Addressing Mode : Effective Address is calculated by the sum of 8- or 16 bit displacement and a based indexed address.
E.A.= (BX or BP) + (SI or DI) +( 8 bit displacement (sign extended ) or 16 bit displacement)
Physical Address= E.A + (DS)*1610
Define Direct Addressing
A 16 bit offset address of the data memory location is specified with reference to the DS segment starting address.For.E.g MOV [1020H],5020H instruction transfers a word 5020H to the data memory location at 11020H if DS=1000H.
Define Immediate Addressing.
An 8 bit or 16 bit immediate data follows the instruction. For e.g MOV AX,5020H instruction transfers a word 5020H to the AX register .
Define Register Relative Addressing Mode.
Register Relative Addressing Mode : The Effective Address is Calculated by the sum of 8- or 16 bit displacement and the contents of a base Register or an index Register.
E.A. = content of(BX or BP or SI or DI) + (8 bit displacement (sign extended ) or 16 bit displacement
Physical Address = E.A +(DS)*1610
Compare the 8 bit microprocessors 8080A and 8085.
8080A is the predecessor of 8085. 8085 has the instruction set of 8080A plus some additional ones. Program written for 8080A will be executed by 8085. 8085 and 8080A are not pin compatible. Both require a +5V power supply
What are the limitations of 8085 MPU?
(i) The lower order address bus of the 8085 microprocessor is multiplexed (time shared) with the data bus. The buses need to be demultiplexed.
(ii) Appropriate control signals need to be generated to interface memory and I/O with the 8085.
Write about RST pins in 8085?
In 8085 ,three RST pins are available, such as RST 7.5 ,RST 6.5 , RST 5.5
RST represents Restart Interrupts. These are vectored interrupts that transfer the program control to specific memory locations. They have higher priorities than the INTR interrupt. Among these three, the priority order is 7.5,6.5,5.5.
List the four operations commonly performed by MPU( Micro processing Unit)?
Memory Read : Reads data (or instructions) from memory.Memory Write: Writes Data (or instructions) into memory.I/O Read: Accepts data from input devices
.I/O Write: Sends data to output devices
What is compiler?
Compiler is a program that translates English like words of a high level language into the machine language of a computer. A compiler read a given program ,called a source code, in its entirely and then translates the program into the machine language, which is called an Object Code.
What do you mean ‘ Data Width’?
Data Width is the width of the ALU. An 8 bit ALU can add / subtract/ multiply etc.. two 8 bit numbers . In many cases, the external data bus is the same width as the ALU, but not always. The 8088 had a 16 bit ALU and 8 bit bus , while the modern
List the limitations of 8 bit microprocessor:
Lower Execution Speed
It can address less memory size
Few instructions are available
Define Real Time
Real Time Systems are those in which timeliness is as important as the correctness of the outputs, although this does not mean that they have to be “fast systems”.
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