Intel Microprocessor Interview Preparation Guide
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Intel Microprocessor job interview preparation guide for freshers and experienced candidates. Number of Intel Microprocessor frequently asked questions(FAQs) asked in many Intel Microprocessor interviews

25 Intel Microprocessor Questions and Answers:

1 :: Explain briefly the characteristics of the program invisible registers?

- The program invisible registers are used to access and specify the address tables of global and local descriptor tables.

- Since these types of register cannot be accessed directly by a program they are called invisible registers.

- The Global Descriptor table register contains the limit and the base addresses for the descriptor table. The same applies for the Interrupt descriptor table register.

- Since the maximum length is limited to 64 Kbytes the limit of each descriptor table is limited to 16 bits.

- The GTDR is loaded with the address of the global descriptor table whenever a protected mode operation is required.

2 :: Explain the 8279 operation?

- The 8279 is basically a programmable keyboard and a component for display interfacing.

- The 8279 can scan and also encode a 64 key keyboard as well as a numerical display of 16 digits.

- The keyboard has a buffer based on FIFO to store up to 8 keys after which the processor must retrieve a character.

- It contains 8 lines that can be used to connect to 8 columns of a keyboard. There are two additional lines for STB keys.

- Once a key is pressed they are automatically debounced and it can function using two modes -key lockout and n-key roller.

- On simultaneous presses only the first key is detected. In case of n-key rollover mode all simultaneous presses are detected and stored in the internal buffer.

3 :: Describe briefly any three types of transmission?

The various types of commonly used transmissions are as follows:

- Simplex Transmission: This type of data transmission involves data to be moved only in one direction. In this no data can be sent back using the same channel. A
good example of this form of transmission can be found in a keyboard.

- Half Duplex Transmission: This type of transmission allows data to be transferred in both directions but not at the same time. One end transmits while the other

- Full Duplex Transmission: In this type of transmission data can be sent and received at the same time. There are no two different modes such as transmit and

4 :: Briefly mention the differences between VGA and CGA graphics?

The characteristics of CGA are as follows:

- The CGA or the Color/Graphics adapter was the first color graphics card for IBM pc`s.

- It contain 16KB of video memory and used an Rca jack to connect to a Tv or monitor ( NTSC compatible).

- It could also be connected to a RBGI interface CRT monitor (4-bit).

The characteristics of VGA graphics are as follows:

- The VGA or the video graphics array was a hardware introduced with the IMB PS/2 computers.

- It has been widely adopted world over and now actually implies the analog computer display standard.

- Eventually after much modifications by other manufacturers the VGA was superseded by SVGA.

5 :: Describe briefly the external and internal bus of the 8088 processor?

- Internal Data Bus: As its name suggests the internal data bus only works inside a CPU that is internally. It is able to communicate with the internal cache memories of

the CPU. Since they are internally placed they are relatively quick and are now affected by the rest of the computer.

- External Data bus: This type of bus is used to connect and interface the computer to its connected peripheral devices. Since they are external and do not lie within the
circuitry of the cpu they are relatively slower.

- The 8088 processor in itself contains a 16-bit internal data bus coupled with a 20-bit address register. This allows the processor to address to a maximum of 1 MB

6 :: Explain briefly the role of the 8284 processor?

- The 8284 is considered to be a supporting part for microprocessors. It is responsible for the generation of clock signals.

- The clock generator forms an intrinsic part of a circuit as without it every component in the system would have to create a signal for it independently.

- When F/C’ is at logic, the oscillator output is steered through to the divide-by-3 counter.

7 :: What do you understand by VESA local bus? Mention the cons of using it?

VESA stands for Video Electronics Standards Association. It is used for the transmission of high speed input-output operations as well as to directly access the

- It comprises of a various videos card and monitor manufacturers , they creates standards to define the resolution, number of colors, and other display properties.

- In this way graphics cards have direct access to the processor and system memory. It does not suffer from limitations of the ISA bus.

Some of the cons of using VESA are as follows:

- VESA suffers from interoperability issues.

- VESA Standard is also unreliable as there are multiple cases in which the hardware such as the monitor or the card to display are unstable and buggy.

- Highly dependent on the hardware configuration, getting the right combination is generally difficult.

- VLB cards are not easy to install / service.

8 :: Mention a few facts and properties of ENIAC?

- ENIAC is also known as Electronic Numerical Integrator And Computer.

- It is considered to be the first general-purpose electronic computer.

- It was completely capable computer which can be reprogrammed to solve computing related problems.

- The ENIAC was used by the Americans for the first time to calculate the trajectories of artillery shells.

- ENIAC was designed and created by John Mauchly and J. Presper Eckert of the University of Pennsylvania.

9 :: Explain segments their pro`s and a method for their implementation?

- The division of address space into logical sections is known as segmentation and each such space is known as a segment.

- In order to access a specific memory location, a program must specify both the segment number and the offset contained in that segment. Segment memory addressing divides the memory into many segments.

- One of the advantages of memory segmentation is that only 16 bit registers are
required to both store segment base address as well as offset address. Due to this the designing of the memory is simple.

- By using segmentation there is the advantage of relocability as well.

10 :: Explain in Pentium processors how memory management has been improved?

- By adding a paging unit and a new system in the memory system the management of it has been improved upon.

- Paging Unit: The paging mechanism works on 4KB memory pages or with a
new extension available to the Pentium with 4MB memory pages.

- Memory-management mode: The system memory-management mode (SMM) is on
the equal levels such as the protected mode, real mode, and virtual mode. Still the memory management mode function as a manager. High-level system functions
such as power management and security are taken care of by it.