1.Define Computer Architecture
Computer Architecture Is Defined As The Functional Operation Of The Individual H/W Unit In A Computer System And The Flow Of Information Among The Control Of Those Units
2.Define Computer H/W
Computer H/W Is The Electronic Circuit And Electro Mechanical Equipment That Constitutes The Computer
3. What Is Meant By Cache Memory ?
A Memory That Is Smaller And Faster Than Main Memory And That Is Interposed Between The Cpu And Main Memory. The Cache Acts As A Buffer For Recently Used Memory Location
4.what is locality of reference?
Many instruction in localized area of the program are executed repeatedly during some time period and the remainder of the program is accessed relatively infrequently .this is referred as locality of reference.
5.what is IO mapped input output?
A memory reference instruction activated the READ M (or)WRITE M control line and does not affect the IO device. Separate IO instruction are required to activate the READ IOand WRITE IO lines ,which cause a word to be transferred between the address aio port and the CPU. The memory and IO address space are kept separate.
6.specify the three types of the DMA transfer techniques?
Single transfer mode(cyclestealing mode)
Block Transfer Mode(Brust Mode)
Demand Transfer Mode
Cascade Mode
7. why is memory refreshing circuit needed ?
al cells on the corresponding yow to be read and refreshed during both read and write operation .the contents of the d ram are maintained each row of cell must be accessed periodically once every 2 – 16 ms. refresh circuit usually performs this function . automatically
8 what are the functions of control unit ?
the memory arithmetic and logic ,and input and output units store and process information and perform i/p and o/p operation, the operation of these unit must be co ordinate in some way this is the task of control unit the cu is effectively the nerve center that sends the control signal to other units and sence their states.
9.What is an interrupt?
An interrupt is an event that causes the execution of one program to be suspended and another program to be executed.
10.What are the uses of interrupts?
• Recovery from errors
• Debugging
• Communication between programs
• Use of interrupts in operating system
11.Define vectored interrupts.
In order to reduce the overhead involved in the polling process, a device requesting an interrupt may identify itself directly to the CPU. Then, the CPU can immediately start executing the corresponding interrupt-service routine. The term vectored interrupts refers to all interrupt-handling schemes base on this approach.
12. What is the need for reduced instruction chip?
1. Relatively few instruction types and addressing modes.
2. Fixed and easily decoded instruction formats.
3. Fast single-cycle instruction execution.
4. Hardwired rather than microprogrammed control.
13. Name any three of the standard I/O interface.
1. SCSI (small computer system interface),bus standards
2. Back plane bus standards
3. IEEE 796 bus (multibus signals)
4. NUBUS
5. IEEE 488 bus standard
15.Explain the pipeline types.
1. Instruction pipeline
2. Arithmetic pipeline
16. Explain the various classifications of parallel structures.
1. SISD (single instruction stream single data stream
2. SIMD(single instruction stream multiple data stream
3. MIMD(multiple instruction stream multiple data stream
4. MISD(multiple instruction stream single data stream
17. What is absolute addressing mode?
The address of the location of the operand is given explicitly as a part of the instruction.
Eg. Move a , 2000
18. Specify three types of data transfer techniques.
1. Arithmetic data transfer
2. Logical data transfer
3. Programmed control data transfer
19. What is the role of MAR and MDR?
The MAR (memory address register) is used to hold the address of the location to or from which data are to be transferred and the MDR(memory data register) contains the data to be written into or read out of the addressed location.
20. What are the various types of operations required for instructions?
1. Data transfers between the main memory and the CPU registers
2. Arithmetic and logic operation on data
3. Program sequencing and control
4. I/O transfers
21. What is the role of IR and PC?
Instruction Register (IR) contains the instruction being executed. Its output is available to the control circuits, which generate the timing signals for controlling the processing circuits needed to execute the instructions. The Program Counter (PC) register keeps track of the execution of the program. It contains the memory address of the instruction currently being executed . During the execution of the current instruction, the contents of the PC are updated to correspond to the address of the next instructions to be executed.
22.Define memory access time?
The time that elapses between the initiation of an operation and completion of that operation ,for example ,the time between the READ and the MFC signals .This is Referred to as memory access time.
23. Define memory cycle time.
The minimum time delay required between the initiations of two successive memory operations, for example, the time between two successive READ operations.
24.Define Static Memories.
Memories that consist of circuits capable of retaining the state as long as power is applied are known as static memories.
25.Distinguish Between Static RAM and Dynamic RAM?
Static RAM are fast, but they come at high cost because their cells require several transistors. Less expensive RAM can be implemented if simpler cells are used. However such cells do not retain their state indefinitely; Hence they are called Dynamic RAM.
26.Distiguish between asynchronies DRAM and synchronous RAM.
The specialized memory controller circuit provides the necessary control signals, RAS And CAS ,that govern the timing. The processor must take into account the delay in the response of the memory. Such memories are referred to as asynchronous DRAMS. The DRAM whose operations is directly synchronized with a clock signal. Such Memories are known as synchronous DRAM
27.what are the various units in the computer?
1,input unit
2.output unit
3.control unit
4.memory unit
5.arithmetic and logical unit
28.what is an I/O channel?
An i/o channel is actually a special purpose processor, also called peripheral processor. The main processor initiates a transfer by passing the required information in the input output channel. the channel then takes over and controls the actual transfer of data.
29.what is a bus?
A collection of wires that connects several devices is called a bus.
30.Define word length?
Each group of n bits is referred to as a word of information and n is called the word length.
31.explain the following the address instruction?
1.three-address instruction-it can be represented as
add a,b,c
Operands a,b are called source operand and c is called destination operand.
2.two-address instruction-it can be represented as
add a,b
3.one address instruction-it can be represented as
add a
4.1 1/2 address instruction
it can be represented the type of instruction in which one address always refers to a location in the main memory and the other, shorter address always refers to a cpu register, is intermediate to the one-two-address formats because of this property is called I ½ address format.
5.zero address instruction.
It is also possible to use instruction where the location s of all operand are defined implicitly. This operand of the use of the method for storing the operand in which called push down stack. Such instructions are sometimes referred to us zero address instruction. 32.what is the straight-line sequencing?
the cpu control circuitry automatically proceed to fetch and execute instruction, one at a time in the order of the increasing addresses. This is called straight line sequencing.
33.what is the role of pc?
The cpu contains a register called the program counter, which holds the address of instruction to be executed next.. to begin the execution of the program the address of its First instruction must be placed into the pc.
34.what are steps for execution of a complete instruction?
1.fetch the instruction.
2.fetch the first operand (the contents of the memory location pointed by the address field of the instruction.)
3.perform the calculation.
4.load the result.
