1.CPU INSTRUCTION AND EXECUTION CYCLE: The primary function of the cpu of a computer is to execute the sequence of instructions stored ina memory which is an external to the cpu.The cpu must first fetch an instruction from the memory before it can be executed .The sequence of operations involved in processing an instruction constitutes an instruction cycle.This can be sub divided into two major phases i.e., fetch phase and execution phase.These two phases are performed in two cosecutive time slots under the control of a clock.Hence these two operations are called as cycles .The time needed to complete the execution of an instruction is known as INSTRUCTION CYCLE time . a.FETCH CYCLE:The instruction is obtained from main memory during the fetch cycle.The fetch operation can be described as \"send the address of the next instruction to memory and recieve the instruction from the memory\". b.EXECUTION CYCLE:The execution cycle includes decoding the instruction fetching of the required operand and performing the operations specified by aninstructions opcode.In other words it can be stated as \"Decode the fetched instruction if the operand is specified in the memory then fetch that operand and execute the instruction \". **INSTRUCTION CYCLE: Thus the fetch and execute operations are carried out in synchronism with a clock is known as instruction cycle i.e.,IC=FC+EC. 3.a.INSTUCTION FORMAT:Instruction format has one or more number of fields.The first field is called as operation code field or opcode fielde which indicates type of operations to be performed by the cpu.It also contains other fields known as operand fields.The cpu executes the instructions using the information which resides in these fields. b.WORD SIZE:A memory unit stores binary information in group of bits called words.The number of bits in each word is often refered to as the WORD SIZE of a computer.Each word is stored in one memory register.The word size in micro and mini computers ranges from 8 to 32 bits, and large computers usually have 32 or more bits in a word. c.CLOCK RATE:A clock is a square wave , which is used to synchronize various devices in the microprocessor and the system.Every microprocessor system requires a clock for its functioning.The time taken for the microprocessor and the system to execute an instruction is called clockrate. 4.FUNCTION OF GENERAL PURPOSE AND SPECIAL PURPOSE REGISTERS: General purpose registers are available to store any transient data required by the program.For example, when a program is interrupted its state, ie: the value of the registers such as the program counter, instruction register or memory address register - may be saved into the general purpose registers, ready for recall when the program is ready to start again.In general the more registers a CPU has available, the faster it can work. A Special Function Register (or Special Purpose Register, or simply Special Register) is a register within a microprocessor, which controls or mon.

1. 1.CPU INSTRUCTION AND EXECUTION CYCLE:
The primary function of the cpu of a computer is to execute the sequence of instructions stored
ina memory which is an external to the cpu.The cpu must first fetch an instruction from the
memory before it can be executed .The sequence of operations involved in processing an
instruction constitutes an instruction cycle.This can be sub divided into two major phases i.e.,
fetch phase and execution phase.These two phases are performed in two cosecutive time slots
under the control of a clock.Hence these two operations are called as cycles .The time needed to
complete the execution of an instruction is known as INSTRUCTION CYCLE time .
a.FETCH CYCLE:The instruction is obtained from main memory during the fetch cycle.The
fetch operation can be described as "send the address of the next instruction to memory and
recieve the instruction from the memory".
b.EXECUTION CYCLE:The execution cycle includes decoding the instruction fetching of the
required operand and performing the operations specified by aninstructions opcode.In other
words it can be stated as "Decode the fetched instruction if the operand is specified in the
memory then fetch that operand and execute the instruction ".
**INSTRUCTION CYCLE:
Thus the fetch and execute operations are carried out in synchronism with a clock is known as
instruction cycle i.e.,IC=FC+EC.
3.a.INSTUCTION FORMAT:Instruction format has one or more number of fields.The first field
is called as operation code field or opcode fielde which indicates type of operations to be
performed by the cpu.It also contains other fields known as operand fields.The cpu executes the
instructions using the information which resides in these fields.
b.WORD SIZE:A memory unit stores binary information in group of bits called words.The
number of bits in each word is often refered to as the WORD SIZE of a computer.Each word is
stored in one memory register.The word size in micro and mini computers ranges from 8 to 32
bits, and large computers usually have 32 or more bits in a word.
c.CLOCK RATE:A clock is a square wave , which is used to synchronize various devices in the
microprocessor and the system.Every microprocessor system requires a clock for its
functioning.The time taken for the microprocessor and the system to execute an instruction is
called clockrate.
4.FUNCTION OF GENERAL PURPOSE AND SPECIAL PURPOSE REGISTERS:
General purpose registers are available to store any transient data required by the program.For
example, when a program is interrupted its state, ie: the value of the registers such as the
program counter, instruction register or memory address register - may be saved into the general
purpose registers, ready for recall when the program is ready to start again.In general the more

2. registers a CPU has available, the faster it can work.
A Special Function Register (or Special Purpose Register, or simply Special Register) is a
register within a microprocessor, which controls or monitors various aspects of the
microprocessor's function. Depending on the processor architecture, this can include, but is not
limited to:
-I/O and peripheral control (such as serial ports or general-purpose IOs)
-timers
-stack pointer
-stack limit (to prevent overflows)
-program counter
-subroutine return address
-processor status (servicing an interrupt, running in protected mode, etc.)
-condition codes (result of previous comparisons)
Because special registers are closely tied to some special function or status of the processor, they
might not be directly written by normal instructions (such as adds, moves, etc.). Instead, some
special registers in some processor architectures require special instructions to modify them. For
example, the program counter is not directly writeable in many processor architectures. Instead,
the programmer uses instructions such as return from subroutine, jump, or branch to modify the
program counter. For example, the condition code register might not directly writable, instead
being updated only by compare instructions.
5.SEMI CONDUTOR BASED MICROPROCESSORS:
Microprocessor is a computer processor which incorporates the functions of a computer's central
processing unit (CPU) on a single integrated circuit (IC),or at most a few integrated circuits.The
microprocessor is a multipurpose, clock driven, register based, programmable electronic device
which accepts digital or binary data as input, processes it according to instructions stored in its
memory, and provides results as output. Microprocessors contain both combinational logic and
sequential digital logic. Microprocessors operate on numbers and symbols represented in the
binary numeral system.
It has limitations on the size of data. The applications are limited by the physical address space.
The analog signals cannot be processed directly and digitizing the analog signals introduces
errors. The speed of execution is slow and so real time applications are not possible. Most of the
microprocessors does not support floating point operations.
6.DISTINGUISHING CHARACTERISTICS OF PRIMARY AND SECONDARY STORAGE:
Primary memory is the main memory (Hard disk, RAM) where the operating system resides.
Secondary memory can be external devices like CD, floppy magnetic discs etc. secondary

3. storage cannot be directly accessed by the CPU and is also external memory storage.
Difference between Primary storage and secondary storage
- Primary memory storages are temporary; where as the secondary storage is permanent.
- Primary memory is expensive and smaller, where as secondary memory is cheaper and larger
- Primary memory storages are faster, where as secondary storages are slower.
- Primary memory storages are connected through data buses to CPU, where as the secondary
storages are connect through data cables to CPU
7.DEVICES USED TO IMPLEMENT PRIMARY STORAGE:
Primary Storage Devices: Generally smaller in size, are designed to hold data temporarily and
are internal to the computer. They have the fastest data access speed, and include RAM and
cache memory.A primary storage device is any storage device or component that can store
nonvolatile data in computers, servers and other computing devices. It is used to hold/store data
and applications temporarily or for a shorter period of time while the computer is
running.Primary storage is also known as main storage, main memory or internal memory.
Primary storage devices are internal to the system and are the fastest of the memory/storage
device category. Typically, primary storage devices have an instance of all the data and
applications currently in use or being processed. The computer fetches and keeps the data and
files it in the primary storage device until the process is completed or data is no longer required.
Random access memory (RAM), graphic card memory and cache memory are common
examples of primary storage devices.
8.COMPARISION OF SECONDARY STORAGE ALTERNATIVES:
Storage
Speed
Capacity
Relative Cost
Permanent
Registers
Fastest
Lowest
Highest
No
RAM
Very Fast

4. Low/Moderate
High
No
Floppy Disk
Very Slow
Low
Low
Yes
Hard Disk
Moderate
Very High
Very Low
Yes
Storage
Speed
Capacity
Relative Cost
Permanent
Registers
Fastest
Lowest
Highest
No
RAM
Very Fast
Low/Moderate
High
No
Floppy Disk
Very Slow
Low
Low
Yes
Hard Disk
Moderate
Very High

5. Very Low
Yes
Solution
1.CPU INSTRUCTION AND EXECUTION CYCLE:
The primary function of the cpu of a computer is to execute the sequence of instructions stored
ina memory which is an external to the cpu.The cpu must first fetch an instruction from the
memory before it can be executed .The sequence of operations involved in processing an
instruction constitutes an instruction cycle.This can be sub divided into two major phases i.e.,
fetch phase and execution phase.These two phases are performed in two cosecutive time slots
under the control of a clock.Hence these two operations are called as cycles .The time needed to
complete the execution of an instruction is known as INSTRUCTION CYCLE time .
a.FETCH CYCLE:The instruction is obtained from main memory during the fetch cycle.The
fetch operation can be described as "send the address of the next instruction to memory and
recieve the instruction from the memory".
b.EXECUTION CYCLE:The execution cycle includes decoding the instruction fetching of the
required operand and performing the operations specified by aninstructions opcode.In other
words it can be stated as "Decode the fetched instruction if the operand is specified in the
memory then fetch that operand and execute the instruction ".
**INSTRUCTION CYCLE:
Thus the fetch and execute operations are carried out in synchronism with a clock is known as
instruction cycle i.e.,IC=FC+EC.
3.a.INSTUCTION FORMAT:Instruction format has one or more number of fields.The first field
is called as operation code field or opcode fielde which indicates type of operations to be
performed by the cpu.It also contains other fields known as operand fields.The cpu executes the
instructions using the information which resides in these fields.
b.WORD SIZE:A memory unit stores binary information in group of bits called words.The
number of bits in each word is often refered to as the WORD SIZE of a computer.Each word is
stored in one memory register.The word size in micro and mini computers ranges from 8 to 32
bits, and large computers usually have 32 or more bits in a word.
c.CLOCK RATE:A clock is a square wave , which is used to synchronize various devices in the
microprocessor and the system.Every microprocessor system requires a clock for its
functioning.The time taken for the microprocessor and the system to execute an instruction is
called clockrate.
4.FUNCTION OF GENERAL PURPOSE AND SPECIAL PURPOSE REGISTERS:

6. General purpose registers are available to store any transient data required by the program.For
example, when a program is interrupted its state, ie: the value of the registers such as the
program counter, instruction register or memory address register - may be saved into the general
purpose registers, ready for recall when the program is ready to start again.In general the more
registers a CPU has available, the faster it can work.
A Special Function Register (or Special Purpose Register, or simply Special Register) is a
register within a microprocessor, which controls or monitors various aspects of the
microprocessor's function. Depending on the processor architecture, this can include, but is not
limited to:
-I/O and peripheral control (such as serial ports or general-purpose IOs)
-timers
-stack pointer
-stack limit (to prevent overflows)
-program counter
-subroutine return address
-processor status (servicing an interrupt, running in protected mode, etc.)
-condition codes (result of previous comparisons)
Because special registers are closely tied to some special function or status of the processor, they
might not be directly written by normal instructions (such as adds, moves, etc.). Instead, some
special registers in some processor architectures require special instructions to modify them. For
example, the program counter is not directly writeable in many processor architectures. Instead,
the programmer uses instructions such as return from subroutine, jump, or branch to modify the
program counter. For example, the condition code register might not directly writable, instead
being updated only by compare instructions.
5.SEMI CONDUTOR BASED MICROPROCESSORS:
Microprocessor is a computer processor which incorporates the functions of a computer's central
processing unit (CPU) on a single integrated circuit (IC),or at most a few integrated circuits.The
microprocessor is a multipurpose, clock driven, register based, programmable electronic device
which accepts digital or binary data as input, processes it according to instructions stored in its
memory, and provides results as output. Microprocessors contain both combinational logic and
sequential digital logic. Microprocessors operate on numbers and symbols represented in the
binary numeral system.
It has limitations on the size of data. The applications are limited by the physical address space.
The analog signals cannot be processed directly and digitizing the analog signals introduces
errors. The speed of execution is slow and so real time applications are not possible. Most of the
microprocessors does not support floating point operations.

7. 6.DISTINGUISHING CHARACTERISTICS OF PRIMARY AND SECONDARY STORAGE:
Primary memory is the main memory (Hard disk, RAM) where the operating system resides.
Secondary memory can be external devices like CD, floppy magnetic discs etc. secondary
storage cannot be directly accessed by the CPU and is also external memory storage.
Difference between Primary storage and secondary storage
- Primary memory storages are temporary; where as the secondary storage is permanent.
- Primary memory is expensive and smaller, where as secondary memory is cheaper and larger
- Primary memory storages are faster, where as secondary storages are slower.
- Primary memory storages are connected through data buses to CPU, where as the secondary
storages are connect through data cables to CPU
7.DEVICES USED TO IMPLEMENT PRIMARY STORAGE:
Primary Storage Devices: Generally smaller in size, are designed to hold data temporarily and
are internal to the computer. They have the fastest data access speed, and include RAM and
cache memory.A primary storage device is any storage device or component that can store
nonvolatile data in computers, servers and other computing devices. It is used to hold/store data
and applications temporarily or for a shorter period of time while the computer is
running.Primary storage is also known as main storage, main memory or internal memory.
Primary storage devices are internal to the system and are the fastest of the memory/storage
device category. Typically, primary storage devices have an instance of all the data and
applications currently in use or being processed. The computer fetches and keeps the data and
files it in the primary storage device until the process is completed or data is no longer required.
Random access memory (RAM), graphic card memory and cache memory are common
examples of primary storage devices.
8.COMPARISION OF SECONDARY STORAGE ALTERNATIVES:
Storage
Speed
Capacity
Relative Cost
Permanent
Registers
Fastest
Lowest

8. Highest
No
RAM
Very Fast
Low/Moderate
High
No
Floppy Disk
Very Slow
Low
Low
Yes
Hard Disk
Moderate
Very High
Very Low
Yes
Storage
Speed
Capacity
Relative Cost
Permanent
Registers
Fastest
Lowest
Highest
No
RAM
Very Fast
Low/Moderate
High
No
Floppy Disk
Very Slow
Low
Low

9. Yes
Hard Disk
Moderate
Very High
Very Low
Yes