Important Computer Architecture Interview Questions Part – 4

What Is Vertical Microcode?

Vertical microcode can be considered to be a segment of code or operators that have been clubbed together into fields. In this field every micro operation is given a unique value.

Explain About Designing Strategy Of A Control Unit Coded On Vertical Code?

A no operation NOP can be included in each field if necessary.
The remaining micro operations can be distributed among the other operation field bits.
Also micro operations that modify the same registers could be grouped together in the same field.

Can You Explain The Two Hardware Methods To Establish Priority?

Two different ways of establishing hardware priority are Daisy Chaining and parallel priority.

Daisy chaining is a form of a hardware implementation of the polling procedure.
Parallel priority is quicker of the two and uses a priority encoder to establish priorities.
In parallel priority interrupt a register is used for which the bits are separated by the interrupt signals from every device.
The parallel priority interrupt may also contain a mask register which is primarily used to control the status of every request regarding interrupts.

Described Some Of The Common Rules Of Assembly Language?

Some of the common rules of assembly level language are as follows:

In assembly language the label field can be either empty or may specify a symbolic address.
Instruction fields can specify pseudo or machine instructions.
Comment fields can be left empty or can be commented with.
Up to 4 characters are only allowed in the case of symbolic addresses.
The symbolic addresses field are terminated by a comma whereas the comment field begins with a forward slash.

List The Components Of The Ven Neumann Architecture?

The main components of the Von Neumann architecture were as follows:

It consisted of a main memory which would be used to store all the data and instructions.
It would consist of an arithmetic logical unit also known as the ALU. This part was to be able to work with binary data.
It also comprised of a control unit which would be responsible for the interpretation of instructions and their execution.
The control unit would also be controlled by the control unit itself.

Explain About The Major Difficulties Of Pipeline Conflicts In Processors Supporting Pipe Lining?

The following are the main reasons for pipe line conflicts in the processor:

When the same resource is accessed at the same time by two different segments it results in resource conflicts. The only way to resolve this problem is to use separate data memories.
In case an instruction’s execution depends on the result of a previous instruction and that result is unavailable it leads to data dependency conflicts.
Instructions that change the count of the PC can cause a lot of problems. This is prevalent particularly in the case of Branch instructions. A method to resolve this issue is known as delayed load where certain instruction are made to execute in a delayed manner to avoid conflicts.

Described The Different Types Of Fields That Are Part Of An Instruction?

An instruction can be considered to be a command that has been issued to a computer to perform a particular operation. The instruction format contains various field in them such as:

Operation Code Field: Also known as the op code field, this field is used to specify the operation to be performed for the instruction.

Address Field:

This field as its name specifies is used to designate the various addresses such as register address and memory address.

Mode field:

This field specifies as to how effective address is derives or how an operand is to perform.

For ex:

ADD R0, R1. In this case the ADD is the operand whereas the R1, ans R0 are the address fields.

List The Different Types Of Micro-operations?

The micro-operations in computers are classified into the following categories:

Register transfer micro-operations: These type of micro operations are used to transfer from one register to another binary information.
Arithmetic micro-operations: These micro-operations are used to perform on numeric data stored in the registers some arithmetic operations.
Logic micro-operations: These micro operations are used to perform bit style operations / manipulations on non numeric data.
Shift micro operations: As their name suggests they are used to perform shift operations in data store in registers.

Explain Write Through Method?

Considered to be the simplest this method involves the updating of the main memory corresponding to every write operation. With this the cache memory is also updated in parallel in case it also contains the word specified at the address. The primary advantage of this method is data integrity, the primary and the cache memory both contain the same data.

Explain Write Back Method?

In this method only the location in the cache is updated. Whenever such an update occurs a flag is set which makes sure that in case the word is removed from the cache the correct copy is saved to the main memory. This approach is usually taken when a word is constantly updated at frequent intervals.

What Is Associative Mapping?

In this type of mapping the associative memory is used to store content and addresses both of the memory word. This enables the placement of the any word at any place in the cache memory. It is considered to be the fastest and the most flexible mapping form.

Explain Direct Mapping?

In direct mapping the RAM is made use of to store data and some is stored in the cache. An address space is split into two parts index field and tag field. The cache is used to store the tag field whereas the rest is stored in the main memory. Direct mapping`s performance is directly proportional to the Hit ratio.

Explain Vertical Micro Code?

In case of vertical micro code every action is encoded in density.
Vertical micro code are slower but they take less space and their actions at execution time need to be decoded to a signal.

Described The Features Of Assembly Language?

Although Assembly level languages are not easy to understand they are relatively easier as compared to machine level languages.
The programs written in this language are not portable and the debugging process is also not very easy.
The programs developed in assembly language are thoroughly machine dependent.

Explain Virtualization With The Pros And Cons?

In a way virtualization appears similar to emulation but actually it shares hardware resources from the host OS.

This method is slower as compared to partition method but is faster than emulation.
Virtualization had also vast support considering it can also provide with 3d support.
With the help of virtualization it enable users to create virtual clusters.
But virtualization systems require a lot of memory in form of ram.
For virtualization it is mandatory that the virtualized platform has the same architecture as the host pc otherwise due to incompatibilities it is not possible.