The full form of it is :A for Active ,S for Server ,P forPages.
Active Server Pages (ASP), also known as Classic ASP, was introduced in 1998
as Microsoft's first server side scripting engine.
ASP is a technology that enables
scripts in web pages to be executed by an Internet server.
ASP pages have the file extension .asp, and are normally written in VBScript.
ASP.NET - ASP.NET pages are compiled.
ASP.NET has better language support, a large set of user controls, XML-based
components, and integrated user authentication.
ASP.NET pages have the extension .aspx, and are normally written in VB (Visual Basic)
or C# (C sharp).
User controls
in ASP.NET can be written in different languages, including
C++ and Java.
When a browser requests an ASP.NET file, the ASP.NET engine reads the file, compiles and executes the scripts in the file,
and returns the result to the browser as plain HTML.
Why .NET ? OR Advantages of .NET -
1)It is complete technology .Console based ,web based ,client based ,window based applications are in it.
2)It is Language Independent . No need to learn other language.In above 50 + language it can be used.
3) It is Platform Independent .Partially platform independent with editor text which support .NET the Microsoft operating system runs .NET on all of its version .In Linux with MonoExe we can run in it also .Support on windows 7,XP,etc.
4) Automatic Memory Management .By GArbage collector it automatically makes memory management by its algorithm (Disposes,Recall,Algo's)
5)Security
6)It support Interoperability. If project written in VS-6 it can access easi;ly in VS-8.
Note:-
In Notepad .cs can run visual Studio is rich provides help in Dot providing.
.NET Framework:-
Two main components of .NET framework are
1)Frameclass Libraries/Base class libraries
2)Common Language Run-time (Heart of .NET framework)-Here all .NET application are executed .
ADO.NET -Active X Data Object .NET make the code simple.
It is divided into two parts -
1)Connected architecture -It has (example:Desktop required all time connection)
a) Connection object
b) Command object(place where we write query)
c) Data Reader(forward only,read only)
d) Data Adapter
2)Disconnected architecture - It has(example: Laptop requires charging)
a)Data Sets-(Insert /update/delete)
i)Data table
ii) Data Row
iii) Data Column
b)Data Relation
Methods of Command objects:-
1)Sql Data Reader dr =cmd.ExecuteReader();
return type is Sql data Reader dr
When there is single query for multiple results use this blindly for select.query.
2)int i =cmd.Execute non.Query();
use this method when there is data Data manipulate query for insert ,update,delete.
3)object obj = cmd.ExecuteScalar();
use this method for query returning single value .
These are used only in Connected architecture and not in disconnected.
Interface-
1)variables ,constructors are not declared .
2)only methods are declared.
3)they are public access by default so no need to write access.
4)There is contract in class and interface 3methods of interface are 100% compulsory.
Collections:-
In Collection we have
1)Sequential collection .
2)Dictionary collection.
3)Specialized collection.
4)Generic collection.
IC
- Integrated circuits ,we are totally surrounded by IC in today life
hey are made by semiconductors which are like silicon ,germanium ,etc.
have valency 4.
Microprocessor are
made up of different IC .Nowadays,in our day to day life we are
surrounded by different microprocessors ,many people think that they are
only in computers but this not true they are in most of the electronic
instruments like mobiles,smart
phones,refrigerator,Air-conditioner,microwave,and many more
appliances,also in calculators.Microprocessors are also used inother advanced electronic systems, such as computer printers, automobiles,home security systems, radio ,automotive and jet airliners.
Actually
the evolution of Microprocessor was ,it was the Japanese who told in
1960 to INTEL to make microprocessor for doing calculation .Then the
work on it started and finally in 1971 they developed a 4 bit
Microprocessor 4004 which not so powerful but did only the work of
calculator.µΡ symbol is used for
microprocessor.This was the first generation of microprocessor.In this
generation INTEL intorduced the first general purpose 8 bit µΡ with the development of LSI(Large Scale Integration)technology.
Bits :Bit is the smallest unit of binary size which uses only two symbols zero and one.
Byte:It is symbol used to represent eight bits.
B7
B6
B5
B4
B3
B2
B1
B0
Word :A symbol used to represent 16 bits.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Second Generation:- The successor to the 8080 and 6800 were
introduced the Z80,8085 from INTEL,6809 from MOTOROLA,etc.In 1976 8085µΡ of intel was introduced.This µΡs were 8-bit microprocessors. This µΡs had complete µC
(microcomputer) system with CPU(Central Processing Unit),ROM (Read Only
Memory),RAM(Random Access Memory),CLOCK,I/O ports(Input Output),all in
single package. Examples INTEL 8048,8028,MOTOROLA MC 6801,Z80(Zilog) in 1974. There were 12 bit µΡs also developed as a enhancement in 8 bit µΡs example-In 1977,IM6100(Intersil)and T8190(Toshiba). Third Generation:- In this generation 16-bit
microprocessors were introduced with high performance.Example Intel 8086
microprocessor.
Fourth Generation:- In this first 32 -bit µΡs were introduced which can address physical memory of 4GB.Example:- Intel 80386
Fifth Generation:- In this 64 -bit µΡs were introduced. Example:- Intel Pentium,I,II,III and so on.
Generic Block Diagram of Microprocessors:-
A microprocessor includes mainly of blocks and buses to connect them.They are as follows:
Arithmetic Logic Unit (A.L.U.)
Registers
Instruction Decoder
Timing and control
Interrupt Control
Buses
1. A.L.U.:- The main function of it is to to do the arithmetic calculations and logical operations .
They have Flag Registers in it which is used to perform result and to send it.
2.Registers:-There are many several registers in it they are as follow:-
I) Accumulator registers:-It is an 8-bit unit.This are the main
registers which store the result of the arithmetic operations.
II) General Purpose Registers:-
They are as follow :
Register B-It is 8-bit.
Register C-It is 8-bit.
Register D-It is 8-bit.
Register E-It is 8-bit.
Register H - It is 8-bit.
Register L-It is 8-bit.
Temporary Register-It is 8-bit.
They are always used in pairs making 16- bit .The pairs are as follows:
Register B-C pair ,Register D-E pair,Register H-L pair.
III)Status Register:-It is set of flip-flops called Flags.Microprocessor has two flags carry and zero flag.
IV)Program Counter:-It is 16-bit used to store the address of next memory location.
V)Stack Pointer:- It is 16-bit used to store address of a memory called stack.
VI)Instruction Register :-It is8-bit the first byte of instruction is loaded in this register.
3.Instruction
Decoder: As its name suggest it take instruction from Instruction
register and decodes it by driving control section.
4.Timing and Control Section :-It generates signals to control respective devices as by instruction decoder.
5.Interrupt
Control:-It is process which executes certain steps when interrupt
occurs,and decides the priority for the interrupt occur.
6.Buses :There are three types of buses in microprocessor:-
A) Address bus:- It is 16-bit bus with unidirectional.
B)Data bus:- It is 8- bit with bidirectional.
C)Control bus:- Carries signal to execute operation.
Instruction Format-
An instruction is a combination of bit pattern.
They can be viewed as a collection of two parts.One part ,which
gives the task to be performed,is rightly called OPCODE(OPERATION CODE)
and the other part gives the data to be operated on called as
OPERAND.The operand can be specified in many ways.
Instruction for 8085 are of three formats:-
i)One byte instructions
ii)Two byte instructions
iii)Three byte instructions
Block Diagram of 8085 microprocessor :-
Pin Diagram of 8085:-
Signals involved in transferring data and executing instructions in
microprocessor.
·Classification of Signals
8085
is a general purpose microprocessor having 40 pins and works on single power
supply. To study the pin diagram we group the signals into 5 categories:
1.Power Supply 2.Clock Signals 3.Interrupt Signals 4.Address and Data bus 5.Control and Status signals 6.Serial I/O Port 7.DMA Request Signals
The various signals in a microprocessor can be classified as Power supply and Frequency signals: Signals which aids in
supplying power and generating frequency are associated with this type. Pins
like Vcc and ground are classified under this type. Address signals: Signals associated with the lower order
address bus and time multiplexed higher order address bus comes under this type
of signals. Data Signals: Signals associated with data bus comes under
this type. Control and Status Signals: Signals which are associated
with timing and control unit such HOLD, RW’, WR’ etc. comes under this type of
signals. Interrupt Signals: We know
that signals like TRAP, RST 5.5 etc. are interrupt signals. Such signals come
under this category. Serial I/O signals: These signals are used for giving
serial input and output data. Signals like SID, SOD come under this category. Acknowledgement Signals: Signals like INTA’, HLDA acts as
acknowledgement signal for 8085 microprocessor.
Address Bus:
The pins A8-A15 denote the address bus. They are used for the most
significant bit of memory address. Address/Data Bus:
AD0-AD7 constitutes the Address/Data bus. They are time multiplexed. These
pins are used for least significant bits of address bus in the first machine
clock cycle and used as data bus for second and third clock cycle.
But what is a clock cycle? What is first clock cycle and second, third so
on...
A clock cycle is nothing but the time taken between two adjacent pulses of
the oscillator. In simple words clock cycle refers to the transition between o
volts to 5 volts and back to 0 volts. So the first clock cycle means the first
transition of pulse from 0volts to 5 volts and then back to 0 volts. ALE: Address Latch Enable:
In the previous article we saw how ALE helps in demultiplexing the lower
order address and data bus. This signal goes high during the first clock cycle
and enables the lower order address bits. The lower order address bus is added
to memory or any external latch.ALE is on pin number 30. IO/M’:
Consider we have an address to be processed. But how do the processors know
whether the address is for memory or I/O functions? For this purpose a status
signal called IO/M’ is used. This distinguishes whether the address is for
memory or IO. When this pin goes high, the address is for an I/O device. While
the pin goes low, the address is assigned for the memory.IO/M’ is on pin number 34. S0-S1:
S0 and S1 are status signals which provides different status and functions
depending on their status.S0 is on pin number29 and S1 on 33. RD’:
This is an active low signal. That is, an operation is performed when the
signal goes low. This signal is used to control READ operation of the
microprocessor. When this pin goes low the microprocessor reads the data from
memory or I/O device.RD’is on pin number32 WR’:
WR’ is also an active low signal which controls the write operations of the
microprocessor. When this pin goes low, the data is written to the memory or
I/O device.WR’is on pin number31 READY:
READY is used by the microprocessor to check whether a peripheral is ready
to accept or transfer data. A peripheral may be a LCD display or analog to
digital converter or any other. These peripherals are connected to
microprocessor using the READY pin. If READY is high then the periphery is
ready for data transfer. If not the microprocessor waits until READY goes high. HOLD:
This indicates if any other device is requesting the use of address and data
bus. Consider two peripheral devices. One is the LCD and the other Analog to
Digital converter. Suppose if analog to digital converter is using the address
and data bus and if LCD requests the use of address and data bus by giving HOLD
signal, then the microprocessor transfers the control to the LCD as soon as the
current cycle is over. After the LCD process is over, the control is
transferred back to analog and digital converter.HOLD is on pin number 39. HLDA:
HLDA is the acknowledgment signal for HOLD. It indicates whether the HOLD
signal is received or not. After the execution of HOLD request, HLDA goes low.HLDA is on pin number 38. INTR:
INTR is an interrupt request signal. It has the lowest priority among the
interrupts. INTR can be enabled or disabled by using software. Whenever INTR
goes high the microprocessor completes the current instruction which is being
executed and then acknowledges the INTR signal and processes it. INTA’:
Whenever the microprocessor receives interrupt signal. It has to be
acknowledged. This acknowledgement is done by INTA’. So whenever the interrupt
is received INTA’ goes high.INTA’ is on pin number 11. RST 5.5, 6.5, 7.5:
These are nothing but the restart interrupts. They insert an internal
restart function automatically.
All the above mentioned interrupts are maskable interrupts. That is, they
can be enabled or disabled using programs. TRAP:
Among the interrupts of 8085 microprocessor, TRAP is the only non-maskable
interrupt. It cannot be enabled or disabled using a program. It has the highest
priority among the interrupts.
PRIORITY ORDER (From highest to lowest)
TRAP is on pin number 6
RST 7.5 is on pin number 7
RST 6.5 is on pin number 8
RST 5.5 is on pin number 9
INTR is on pin number 10 RESET IN’:
This pin resets the program counter to 0 and resets interrupt enable and
HLDA flip-flops. The CPU is held in reset condition until this pin is high.
However the flags and registers won’t get affected except for instruction
register.RESET IN’is on pin number 36. RESET OUT:
This pin indicates that the CPU has been reset by RESET IN’.RESET OUT is on is on pin number3. X1 X2:
These are the terminals which are connected to external oscillator to
produce the necessary and suitable clock operation.X1 is on pin number 1 and X2 on 2. CLK:
Sometimes it is necessary for generating clock outputs from microprocessors
so that they can be used for other peripherals or other digital IC’s. This is
provided by CLK pin. Its frequency is always same as the frequency at which the
microprocessor operates. SID:
This pin provides serial input data. The serial data on this pin is loaded
into the seventh bit of the accumulator when RIM instruction is executed.
RIM stands for READ INTERRUPT MASK, which checks whether the interrupt is
masked or not. SOD:
This pin provides the serial output data. The serial data on this pin
delivers its output to the seventh bit of the accumulator when SIM instruction
is executed. Vcc and Vss:
Vcc is +5v pin and Vss is ground pin.Vcc is on pin number 40 and Vss on 20.
Thus the pin diagram and signals of 8085 microprocessor are explained in
detail.
