ivrs system

8/2/2019 Ivrs System

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MICROCONROLLER BASEDINTERACTIVE VOICE RESPONSE

SYSTEM


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Abstract

The Interactive Voice Response (IVR) System serves as a bridge

between people and computer databases by connecting the

telephone network with the database. The telephone user can

access the information from anywhere at anytime simply by

dialing a specified number and following an on-line instruction

when a connection has been established. The IVR system uses

pre-recorded or computer generated voice responses to provide

information in response to an input from a telephone caller. The

input may be given by means of touch-tone or Dual Tone Multi-

Frequency (DTMF) signal, which is generated when a caller

presses a key of his/her telephone set, and the sequence of

messages to be played is determined dynamically according to an

internal menu structure (maintained within the IVR application

program) and the user input.

The IVRS system which will be designed will provide an ideal

platform for the operation of start-ups and existing small

concerns. It will be a highly economical and efficient way to

replace the Dialogic card which is very costly and requires a high


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maintenance and regular upgradation. The IVRS system which will

be designed will consist of simple components like microcontroller

and some basic application chips interfaced to a PC which will

have small software running in the backend while the other jobs

are performed on the front end. Microcontroller Based Ivrs For

College Automation Now-A-Days Every Institution Needs

Automation. As A Part Of College automation, We Have Decided

To Do A Project Voice Interactive System For College

Automation. Our Project Allows The User To Know The Students

Attendance And Marks Quickly Through The Telephone Line

Without The Intention Of The College Authority. In The Hardware

Side Embedded System Has Been Used. The Microcontroller

Controls The Whole Hardware. Telephone Line Is Used For

Communication Purpose. Visual Basic Has Been Used For Software

Programming. Presentation In The Class And Outcome Of The

University Are Made Reachable To The Parents By Our Project. It Will

Be Very Obliging To The Parents To Be Acquainted With Their

Sons/DaughtersRecital In The College.


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WHAT IS IVRS SYSTEM

Interactive Voice Response (IVR) product, interactive technology that allows a

computer to detect voice and keypad inputs. IVR technology is used extensively in

telecommunications, but is also being introduced into automobile systems for

hands-free operation. Current deployment in automobiles revolves around satellite

navigation, audio and mobile phone systems. In telecommunications, IVR allows

customers to access a companys database via a telephone touchtone keypad or by

speech recognition, after which they can service their own enquiries by following

the instructions. IVR systems can respond with pre-recorded or dynamically

generated audio to further direct users on how to proceed. IVR systems can be used

to control almost any function where the interface can be broken down into a series

of simple menu choices. In telecommunications applications, such as customer

support lines, IVR systems generally scale well to handle large call volumes.

It has become common in industries that have recently entered the telecom

industry to refer to an Automated Attendant as an IVR. The terms Automated

Attendant and IVRare distinct and mean different things to traditional telecom

professionals, whereas emerging telephony and VoIP professionals often use the
http://en.wikipedia.org/wiki/Customer_supporthttp://en.wikipedia.org/wiki/Customer_supporthttp://en.wikipedia.org/wiki/Automated_attendanthttp://en.wikipedia.org/wiki/Automated_attendanthttp://en.wikipedia.org/wiki/Customer_supporthttp://en.wikipedia.org/wiki/Customer_support


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term IVR as a catch-all to signify any kind of telephony menu, even a basic

automated attendant.

History

The blueprint for IVR began in 1941, when Bell System developed a new tone

dialing methodology. Bell unveiled the first telephone that could dial area codes

using Dual Tone Multi Frequency DTMF technology at the Seattle World Fair in

1962. DTMF telephones enabled the use of inband signaling.

Despite the fact that more companies began using the system in the 1970s to

automate tasks in call centers, the technology was still costly and complicated

which made for low market penetration. However, by the 1980s a number of new

competitors entered the market and uptake of IVR technology started to increase.

When call centers began to migrate to multimedia contact centers in the late 90's,

companies began to invest in web-enablement and Computer Telephony

Integration (CTI) with IVR systems. IVR became vital for call centers deploying

universal queuing and routing solutions and acted as an agent which collected

customer data to enable intelligent routing decisions.
http://en.wikipedia.org/wiki/Bell_Systemhttp://en.wikipedia.org/wiki/DTMFhttp://en.wikipedia.org/wiki/DTMFhttp://en.wikipedia.org/wiki/Bell_Systemhttp://en.wikipedia.org/wiki/DTMFhttp://en.wikipedia.org/wiki/DTMF


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Having remained technologically static since its development in the 1980s, speech

recognition started to become more common and cheaper to deploy. This was due

to increased Computer Processing Power and the migration of Speech applications

from propriety code to the VXML standard. The introduction of the VXML

standard also simplified the integration process between IVR systems and any back

end hosts.

Typical uses

IVR systems are typically used to service high call volumes, reduce cost and

improve the customer experience. Examples of typical IVR applications are:

telephone banking, televoting, and credit card transactions. Large companies use

IVR services to extend the business hours of operation.

Call centers use IVR systems to identify and segment callers. The ability to

identify customers allows the ability to tailor services according to the customer

profile. It also allows the option of choosing automated services. Information can

be fed to the caller allowing choices such as: wait in the queue, choose an

automated service, or request a callback (at a suitable time and telephone number).

The use of computer telephony integration (CTI) will allow the IVR system to look

up the caller line identification (CLI) on a network database and identify the caller.

This is currently accurate for about 80% of inbound calls. In the cases where CLI


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is withheld or unavailable, the caller can be asked to identify themselves by other

methods such as a PIN or password. The use of DNIS will ensure that the correct

application and language is executed by the IVR system.

CTI allows a contact center or organisation to gather information about the caller

as a means of directing their inquiry to an appropriate agent. CTI can also extract

important or relevant information about the individual customer from the database,

making for a more effective and efficient service.

The use of IVR and voice automation enables a company to improve its customer

service and lower its costs, due to the fact that callers queries can be resolved

without the cost of a live agent who, in turn, can be directed to deal with specific

areas of the service. If the caller does not find the information they need, or require

further assistance, the call is then transferred to an agent who can deal with them

directly through CTI integration. This makes for a more efficient system in which

agents have more time to deal with complex interactions, for example, customer

retention, up selling, cross selling and issue resolution. This way, the customer is

more likely to be satisfied with a personalised service and the interaction is likely

to be more fulfilling and rewarding for the agent, as opposed to dealing with basic

enquiries that require yes/no responses, such as obtaining customer details.

Employee satisfaction is important in the telecommunications industry due to the


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fast turnover of staff, IVR is therefore one way of retaining a workforce and

allowing them to do a more effective job.

IVR also enables customer prioritisation. In a system whereby individual

customers may have a different status, for example, a bronze, gold or platinum card

holder, the service will automatically prioritise the individuals call and, in the case

of a platinum card holder, move them to the front of the calling queue.

Voice-Activated Dialers

(VAD) Voice-activated IVR systems are now used to replace the switchboard or

PABX (Private Automatic Branch eXchange) operators and are used in many

hospitals and large businesses to reduce the caller waiting time. An additional

function is the ability to allow external callers to page hospital staff and transfer

the inbound call to the paged person.

Entertainment and Information

The largest installed IVR platforms are used for applications such as tele-voting on

TV game shows such as Pop Idoland Big Brotherwhich can generate enormous

call spikes. Often the network provider will have to deploy Call gapping in the

Public network to prevent Network overload.

The following are some of the more common uses of an IVR:
http://en.wikipedia.org/wiki/Pop_Idolhttp://en.wikipedia.org/wiki/Big_Brother_(TV_series)http://en.wikipedia.org/wiki/Call_gappinghttp://en.wikipedia.org/wiki/Pop_Idolhttp://en.wikipedia.org/wiki/Big_Brother_(TV_series)http://en.wikipedia.org/wiki/Call_gapping


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Mobile (Pay as you go Top up)

Telephone Banking (Balance, payments, and transfers)

Mobile Purchases (particularly for mobile content, such as ringtones and

logos)

Caller identification and routing

Order Placements (Credit Card Payments)

Airline (Ticket booking, Flight arrivals, Flight departures, Checkin)

Adult entertainment (Dating, Chat line etc)

Weather forecasts

Anonymous Access

IVR systems also allow callers to obtain data relatively anonymously. Hospitals

and Clinics have used IVR systems to allow callers to receive anonymous access to

test results. This is information that could easily be handled by a person but the

IVR system is used to preserve privacy and avoid potential embarrassment of

sensitive information or test results. Users are given a passcode to access their

results.

Clinical Trials


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IVR systems are used by pharmaceutical companies and contract research

organizations to conduct clinical trials and manage the large volumes of data

generated. The caller will respond to questions in their preferred language and their

responses will be logged into a database and possibly recorded at the same time to

confirm authenticity. Applications include patient randomization and drug supply

management.

Outbound Calling

IVR systems can be used for outbound calls, as IVR systems are more intelligent

than Dialler systems, they can recognise different line conditions.

RNA Ring No Answer

Answered by Voicemail or Answering machine (In this circumstances they

can leave a message)

Fax Tone (IVR can leave a Fax Message based upon a TIFF Image)

Answer (IVR can tell the customer who is calling and ask them to wait for

an agent)

Recognise Divert messages and abandon call.

IVR uses Call Progress Detection to monitor Line conditions, and report to the

IVR Database.
http://en.wikipedia.org/wiki/Contract_research_organizationhttp://en.wikipedia.org/wiki/Contract_research_organizationhttp://en.wikipedia.org/wiki/Clinical_trialhttp://en.wikipedia.org/wiki/Contract_research_organizationhttp://en.wikipedia.org/wiki/Contract_research_organizationhttp://en.wikipedia.org/wiki/Clinical_trial


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Technologies Used

DTMF signals (entered from the telephone keypad) and natural language speech

recognition interpret the caller's response to voice prompts.

Other technologies include the ability to speak complex and dynamic information

such as an e-mail, news report or weather information using Text-To-Speech

(TTS). TTS is computer generated synthesized speech that is no longer the robotic

voice generally associated with computers. Real voices create the speech in tiny

fragments that are spliced together (concatenated) before being played to the caller.

An IVR can be utilized in several different ways:

1. Equipment installed on the customer premise

2. Equipment installed in the PSTN (Public Switched Telephone Network)

3. Application service provider(ASP).

4. Hosted IVR

A simple voicemail system is different from IVR in that it is person to person

whereas an IVR is person to computer. IVR voiceforms can be used to provide a

more complex voicemail experience to the caller. For example, the IVR could ask

if the caller wishes to hear, edit, forward or remove a message that was just

recorded.
http://en.wikipedia.org/wiki/Dual-tone_multi-frequencyhttp://en.wikipedia.org/wiki/Telephone_keypadhttp://en.wikipedia.org/wiki/Natural_languagehttp://en.wikipedia.org/wiki/Speech_recognitionhttp://en.wikipedia.org/wiki/Speech_recognitionhttp://en.wikipedia.org/wiki/Speech_synthesishttp://en.wikipedia.org/wiki/Application_service_providerhttp://en.wikipedia.org/wiki/Voicemailhttp://en.wikipedia.org/wiki/Dual-tone_multi-frequencyhttp://en.wikipedia.org/wiki/Telephone_keypadhttp://en.wikipedia.org/wiki/Natural_languagehttp://en.wikipedia.org/wiki/Speech_recognitionhttp://en.wikipedia.org/wiki/Speech_recognitionhttp://en.wikipedia.org/wiki/Speech_synthesishttp://en.wikipedia.org/wiki/Application_service_providerhttp://en.wikipedia.org/wiki/Voicemail


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An automatic call distributor(ACD) is often the first point of contact when calling

many larger businesses. An ACD uses digital storage devices to play greetings or

announcements, but typically routes a caller without prompting for input. An IVR

can play announcements and request an input from the caller. This information can

be used to profile the caller and route the call to an agent with a particular skillset.

(A skillset is a function applied to a group of call-center agents with a particular

skill.)

Interactive voice response can be used to front-end a call center operation by

identifying the needs of the caller. Information can be obtained from the caller

such as account numbers. Answers to simple questions such as account balances or

pre-recorded information can be provided without operator intervention. Account

numbers from the IVR are often compared to caller ID data for security reasons

and additional IVR responses are required if the caller ID data does not match the

account record.

IVR call flows are created in a variety of ways. A traditional IVR depended upon

proprietary programming or scripting languages, whereas modern IVR applications

are structured similar to WWW pages, using VoiceXML[1] , CCXML[2], SRGS[3],

SALT or T-XML languages. The ability to use XML developed applications

allows a Web serverto act as an application server, freeing the developer to focus
http://en.wikipedia.org/wiki/Automatic_call_distributorhttp://en.wikipedia.org/wiki/Call_centerhttp://en.wikipedia.org/wiki/Caller_IDhttp://en.wikipedia.org/wiki/WWWhttp://en.wikipedia.org/wiki/VoiceXMLhttp://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-VXML-0http://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-VXML-0http://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-CCXML-1http://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-SRGS-2http://en.wikipedia.org/wiki/Speech_Application_Language_Tagshttp://en.wikipedia.org/wiki/Web_serverhttp://en.wikipedia.org/wiki/Application_serverhttp://en.wikipedia.org/wiki/Automatic_call_distributorhttp://en.wikipedia.org/wiki/Call_centerhttp://en.wikipedia.org/wiki/Caller_IDhttp://en.wikipedia.org/wiki/WWWhttp://en.wikipedia.org/wiki/VoiceXMLhttp://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-VXML-0http://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-CCXML-1http://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-SRGS-2http://en.wikipedia.org/wiki/Speech_Application_Language_Tagshttp://en.wikipedia.org/wiki/Web_serverhttp://en.wikipedia.org/wiki/Application_server


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on the call flow. It was widely believed that developers would no longer require

specialized programming skills, however this has been proven to be misguided as

IVR applications need to understand the human reaction to the application

dialogue. This is the difference between a good user experience and IVR hell.

Higher level IVR development tools are available in recent years to further

simplify the application development process. A call flow diagram can be drawn

with a GUI tool and the application code (VoiceXML or SALT) can be

automatically generated. In addition, these tools normally provide extension

mechanisms for software integration, such as HTTP interface to web site and Java

interface for connecting to a database.

In telecommunications, an audio response unit (ARU) is a device that provides

synthesized voice responses to touch-tone keypresses (DTMF) by processing calls

based on (a) the call-originator input, (b) information received from a database,

and (c) information in the incoming call, such as the time of day.

ARUs increase the number of information calls handled and to provide consistent

quality in information retrieval.

Outsourcing vs. Contact Center Automation
http://en.wikipedia.org/wiki/Telecommunicationshttp://en.wikipedia.org/wiki/DTMFhttp://en.wikipedia.org/wiki/Telecommunicationshttp://en.wikipedia.org/wiki/DTMF


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Contact Centers are very expensive to run, and can be seen as a drain on

companies' operations.[citation needed] Contact Centres are usually seen as Cost Centres,

however the ability to upsell services and products can reduce operational

expenditure.

Methods of reducing Contact Center running costs include outsourcing and

automation. Outsourcing to other countries can reduce operational expenditure by

as much as 30%, however, differences in culture and language can prove

problematic for customers, whose dissatisfaction can lead to customer complaints

and loss of business. Also if is more difficult to upsell to customers from foreign

Contact Centres.

Automation in a Contact Center can also reduce operational expenditure by around

30% though the introduction of technologies such as customer profiling, CTI, and

IVR using speech recognition. The use of automation in the contact center

promotes efficiency, allowing contact centers to be located in the country from

which the call is originated. Customer satisfaction can be monitored by the use of

customer survey applications. The information from survey applications can be

used to improve customer service.

VoIP
http://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Outsourcinghttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Outsourcing


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The increased usage ofVoIP in voice networks is likely to affect how IVR will be

used in voice networks, this is due to the introduction of protocols such as SIP. The

introduction of SIP means that point to point communications is no longer

restricted to voice calls but can now be extended to multimedia technologies such

as video. This will bring a new meaning to automated services as IVR extends its

reach to video calls. Many IVR manufacturers are currently working on IVVR

(Interactive Voice and Video Response) systems, especially for the mobile phone

networks. The use of video will give IVR systems the ability to use graphical and

video information to assist the caller.

The introduction of video IVR may allow systems in the future the ability to read

emotions and facial expressions. It may be used to identify the caller, using

technology such as Iris scan or other biometric means. Recordings of the caller

may be stored to monitor certain transactions, and will be used to reduce identity

fraud.

Unified Communications in the SIP Contact Center

With the introduction of SIP Contact Centers, Automation has finally come of age.

Calls arriving at a SIP contact Center must now be queued against a SIP IVR

system. Call Control in a SIP Contact Center is controlled by VXML scripting

which is an extension of the language used to write modern IVR Applications. As
http://en.wikipedia.org/wiki/VoIPhttp://en.wikipedia.org/wiki/Session_initiation_protocolhttp://en.wikipedia.org/wiki/Session_initiation_protocolhttp://en.wikipedia.org/wiki/VoIPhttp://en.wikipedia.org/wiki/Session_initiation_protocolhttp://en.wikipedia.org/wiki/Session_initiation_protocol


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calls are queued in the SIP Contact Center the IVR system can provide Treatment,

Automation, Wait for a fixed period, or play music. Inbound Calls to a SIP Contact

Center must be queued or terminated against a SIP end Point. In addition SIP IVR

systems can be used to replace agents directly by the use of BBUA (Back to Back

User agents).

] Interactive Messaging Response (IMR)

As communications have migrated to multimedia so has Automation. The

introduction of Instant Messaging (IM) in Contact Centers is starting to take off.

Agents can handle up to 6 different IM conversations at the same time and so agent

productivity is increasing. IVR systems are now starting to handle IM

conversations using existing Speech Recognitian Technology. This is different

from email handeling as email automated response is based on key word spotting.

IM conversations are different to email as IM is conversational. The use of texting

abbreviations and smilies requires different grammars than those currently used for

speech recognition. IM is also starting to replace texting on Multimdeia Mobile

handsets and is expected to become more widely used.

Hosted vs. On-Premise IVR


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With the introduction of Web services into the Contact Center, integration has been

simplified. The use of Web based applications allow IVR applications to be hosted

remotely from the Contact Center. This allows the use of hosted IVR applications

using speech to be made available to smaller Contact Centers across the globe and

is likely to lead to an expansion of ASP (Application Service Providers).

IVR applications can also be hosted in the public network, which do not require

contact centre integration. This will include public announcement messages or

message services for small business. It is also possible to use two prong IVR

services where the initial IVR application is used to route the call to the

appropriate contact centre. This can be used to balance loading across multiple

contact centres or provide business continuity in the event of system outage.

Criticism

IVR is sometimes criticized as being unhelpful and difficult to use due to poor

design and lack of appreciation of the caller's needs.[4] Some callers object to

providing voice response to an automated system and prefer speaking with a

human respondent. A properly designed IVR application should provide the caller's

needs promptly and with a minimum of complexity. [neutrality disputed] However some

companies use IVR to reduce operational costs and will not offer similar services

using agents. Such services tend to frustrate customers who feel that their right to
http://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-IVR-3http://en.wikipedia.org/wiki/Wikipedia:Neutral_point_of_viewhttp://en.wikipedia.org/wiki/Interactive_voice_response#cite_note-IVR-3http://en.wikipedia.org/wiki/Wikipedia:Neutral_point_of_view


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speak to an agent is being restricted. Companies that deploy such services tend to

ignore customer opinion. Such services are used in debt recovery and giveaways

(Such as Concert tickets, Satellite/Cable Receivers etc).


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STEP DOWN TRANSFORMER 220 VOTL AC TO 9 VOLT AC

DIODE IN 4007 (2)

IC 7805 ( 5 VOLT REGULATOR)

IC 8870 ( DTMF DECODER)

IC 89C2051 ( 20 PIN MICROCONTROLLER FROM 8051 FMILY)

DIP SWITCH ( 4 POINT ) FOR RING DETECTION

IC 555 FOR ( AUTO HOOK UP TELEPHONE LINE)

MAX 232 ( PC INTERFACE )

CRYSTAL 3,58 Mhtz with 8870

AUDIO COUPLING TRANSFORMER

TRANSISTOR BC 558, BC 548

RESISTOR: 470 OHM (4), 22K OHM (2), 10 K OHM (6), 1K OHM (4),

150 OHM (1), 1 MOHM (1)

CPACITOR 10 MFD (1), 1000MFD (2), 1 MFD (4), 33 PF (2), 104 PF

92)


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CIRCUIT WORKING.

In this project we total four IC to provide a automation in the IVRS system. In

this project we use ic 8870 as a DTMF decoder. IC 89s51 as a microcontroller to

interface with the pc and telephone line. IC max232 is RS232 compatible ic and

provide a connectivity between computer and IVRS system. IC 555 provide a

ring detection logic.

In this project we connect landline connection. IN this project first of all we dial

the particular number on college, this phone must be landline phone. As the phone

line is automatic on by a shunt resistance provide by a relay circuit. For ring

detection we use one pc 817 Opto-coupler to provide a optical connectivity

between telephone line ic 555. Output from the opto-coupler is connected to the

pin no 2 of the ic 555. Ic 555 provide a small timer option to provide a delay . Ic

555 provide a square wave to the microcontroller from pin no 3 of the ic. Output

from the ic 555 is connected to the pin no 9 of the controller.

IC 89s51 ( microcontroller ) detect the pulse and count the pulse. Microcontroller

compare with this pulse with the external DIP switch setting. With the help of

DIP switch, we change the ring detection time logic. BY using this DIP switch we

set the total ring count detection .


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After ring detection, first of all we switch on the telephone line by connecting a

resistance across the telephone line with the help of relay coil. As the relay coil is

on , telephone line is on and now we detect the dtmf code.

DTMF CODE is special telephony code , which is use in this ivrs system. As

parents press any digit from the keypad of landline/mobile then this code is receive

by the DTMF decoder. DTMF decoder decode the dtmf signal and this signal is

converted into BCD signal. This BCD signal is further connected to the

microcontroller circuit. Micro-controller get this code in the accumulator and

compare with the internal code set by the operator. Microcontroller convert the

code into serial code and transfer to the PC serial port via Max 232 IC. IC 232

provide a TTL voltage level to the computer .

In the computer we get the signal from hardware circuit and provide a voice

response automation on the telephone line via sound card output. Output from the

sound card is connected to the audio-coupling transformer and then signal is

coupled on the telephone line

IVRS SYSTEM WITH MOBILE INTERFACE


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Program code

ring bit p3.5

call_recv bit p3.7

input equ p1

flag equ 20h

flag0 bit flag.0

flag1 bit flag.1

org 0000h

ljmp main

org 0003h

reti

org 000bh

reti


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org 0013h

reti

org 001bh

reti

org 0023h

ljmp SERIAL

reti

SERIAL:

clr es

jnb ri,$

mov a,sbuf

cjne a,#13d,nxt1_serial

nxt1_serial:

setb es


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reti

main:

mov psw,#00h

mov sp,#040h

mov tmod,#20h

mov th0,#00h

mov tl0,#00h

mov th1,#0ffh

mov tl1,#0ffh

mov tcon,#00h

mov ie,#90h

mov ip,#00h

mov scon,#50h

anl pcon,#7fh


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mov p0,#0ffh

mov p1,#0ffh

mov p2,#0ffh

mov p3,#0ffh

main_lp2:

setb call_recv

clr tr1

clr es

mov a,input

mov r2,a

main_lp1:

clr tr1

clr es

setb call_recv


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jnb ring,$

lcall delay

jb ring,$

jnb ring,$

jb ring,$

djnz r2,main_lp1

setb tr1

setb es

clr call_recv

mov a,#10d

call transmitted

back:

jb flag0,main_lp2

mov a,input


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cjne a,#1d,nxt1

ljmp l1

nxt1: cjne a,#2d,nxt2

ljmp l2


ljmp l3


ljmp l4


ljmp l5


ljmp l6


ljmp l7


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ljmp l8


ljmp l9


ljmp l10


ljmp l11


ljmp l12

nxt12: sjmp back

l1:

mov a,input


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anl a,#0fh

cjne a,#1d,m1

sjmp l1

m1:

mov a,#'1'

call transmitted

ljmp back

l2:

mov a,input

anl a,#0fh

cjne a,#2d,m2

sjmp l2

m2:

mov a,#'2'


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call transmitted

ljmp back

l3:

mov a,input

anl a,#0fh

cjne a,#3d,m3

sjmp l3

m3:

mov a,#'3'

call transmitted

ljmp back

l4:

mov a,input

anl a,#0fh


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cjne a,#4d,m4

sjmp l4

m4:

mov a,#'4'

call transmitted

ljmp back

l5:

mov a,input

anl a,#0fh

cjne a,#5d,m5

sjmp l5

m5:

mov a,#'5'

call transmitted


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ljmp back

l6:

mov a,input

anl a,#0fh

cjne a,#6d,m6

sjmp l6

m6:

mov a,#'6'

call transmitted

ljmp back

l7:

mov a,input

anl a,#0fh

cjne a,#7d,m7


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sjmp l7

m7:

mov a,#'7'

call transmitted

ljmp back

l8:

mov a,input

anl a,#0fh

cjne a,#8d,m8

sjmp l8

m8:

mov a,#'8'

call transmitted

ljmp back


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l9:

mov a,input

anl a,#0fh

cjne a,#9d,m9

sjmp l9

m9:

mov a,#'9'

call transmitted

ljmp back

l10:

mov a,input

anl a,#0fh

cjne a,#10d,m10

sjmp l10


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m10:

mov a,#'0'

call transmitted

ljmp back

l11:

mov a,input

anl a,#0fh

cjne a,#11d,m11

sjmp l11

m11:

mov a,#'*'

call transmitted

ljmp back

l12:


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mov a,input

anl a,#0fh

cjne a,#12d,m12

sjmp l12

m12:

mov a,#'#'

call transmitted

ljmp back

transmitted:

mov sbuf,a

jnb ti,$

setb es

ret

delay:


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mov r0,#75d

loop: djnz r0,loop

ret

DELAY100:

mov r0,#15d

DLP100:

mov r1,#200d

DEL100:

djnz r1,DEL100

djnz r0,DLP100

RET

end END


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HOW TO PROGRAM BLANK CHIP.

8051 micro controller

The 8051

The 8051 developed and launched in the early 80`s, is one of the

most popular micro controller in use today. It has a reasonablylarge amount of built in ROM and RAM. In addition it has the

ability to access external memory.

The generic term `8x51` is used to define the device. The value

of x defining the kind of ROM, i.e. x=0, indicates none, x=3,

indicates mask ROM, x=7, indicates EPROM and x=9 indicates

EEPROM or Flash.

Different micro controllers in market.

PIC One of the famous microcontrollers used in theindustries. It is based on RISC Architecture which makes themicrocontroller process faster than other microcontroller.


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First of all we select and open the assembler and wrote a

program code in the file. After wrote a software we

assemble the software by using internal assembler of the

8051 editor. If there is no error then assembler assemble

the software abd 0 error is show the output window.

now assembler generate a ASM file and HEX file. This hex file is

useful for us to program the blank chip.


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Now we transfer the hex code into the blank chip with the help of

serial programmer kit. In the programmer we insert a blank chip

0f 89s51 series . these chips are multi time programmable chip.

This programming kit is seperatally available in the market and

we transfer the hex code into blank chip with the help of the serial

programmer kit


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WELCOME TO THE WORLD OF THE

MICROCONTROLLERS.

Look around. Notice the smart intelligent systems? Be it the T.V,

washing machines, video games, telephones, automobiles, aero

planes, power systems, or any application having a LED or a LCD

as a user interface, the control is likely to be in the hands of a

micro controller!

Measure and control, thats where the micro controller is at its

best.

Micro controllers are here to stay. Going by the current trend, it is

obvious that micro controllers will be playing bigger and bigger

roles in the different activities of our lives.

These embedded chips are very small, but are designed to

replace components much bigger and bulky In size. They processinformation very intelligently and efficiently. They sense the

environment around them. The signals they gather are tuned into

digital data that streams through tributaries of circuit lines at the

speed of light. Inside the microprocessor collates and calculators.

The software has middling intelligence. Then in a split second, the

processed streams are shoved out.

What is the primary difference between a

microprocessor and a micro controller?


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Unlike the microprocessor, the micro controller can be

considered to be a true Computer on a chip.

In addition to the various features like the ALU, PC, SP and

registers found on a microprocessor, the micro controller alsoincorporates features like the ROM, RAM, Ports, timers, clock

circuits, counters, reset functions etc.

While the microprocessor is more a general-purpose device, used

for read, write and calculations on data, the micro controller, in

addition to the above functions also controls the environment.

8051 micro controller

The 8051

The 8051 developed and launched in the early 80`s, is one of the

most popular micro controller in use today. It has a reasonably

large amount of built in ROM and RAM. In addition it has the

ability to access external memory.

The generic term `8x51` is used to define the device. The value

of x defining the kind of ROM, i.e. x=0, indicates none, x=3,

indicates mask ROM, x=7, indicates EPROM and x=9 indicates


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EEPROM or Flash.

A note on ROM

The early 8051, namely the 8031 was designed without any ROM.This device could run only with external memory connected to it.

Subsequent developments lead to the development of the PROM

or the programmable ROM. This type had the disadvantage of

being highly unreliable.

The next in line, was the EPROM or Erasable Programmable ROM.

These devices used ultraviolet light erasable memory cells. Thus

a program could be loaded, tested and erased using ultra violetrays. A new program could then be loaded again.

An improved EPROM was the EEPROM or the electrically erasable

PROM. This does not require ultra violet rays, and memory can be

cleared using circuits within the chip itself.

Finally there is the FLASH, which is an improvement over the

EEPROM. While the terms EEPROM and flash are sometimes usedinterchangeably, the difference lies in the fact that flash erases

the complete memory at one stroke, and not act on the individual

cells. This results in reducing the time for erasure.

Different microcontrollers in market.

PIC One of the famous microcontrollers used in the industries. It isbased on RISC Architecture which makes the microcontroller process fasterthan other microcontroller.


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INTEL These are the first to manufacture microcontrollers. These arenot as sophisticated other microcontrollers but still the easiest one to learn.

ATMEL Atmels AVR microcontrollers are one of the most powerfulin the embedded industry. This is the only microcontroller having 1kb of rameven the entry stage. But it is unfortunate that in India we are unable to findthis kind of microcontroller.

Intel 8051

Intel 8051 is CISC architecture which is easy to program in assembly language and

also has a good support for High level languages.

The memory of the microcontroller can be extended up to 64k.

This microcontroller is one of the easiest microcontrollers to learn.

The 8051 microcontroller is in the field for more than 20 years. There are lots of

books and study materials are readily available for 8051.


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Derivatives

The best thing done by Intel is to give the designs of the 8051 microcontroller to

everyone. So it is not the fact that Intel is the only manufacture for the 8051 there

more than 20 manufactures, with each of minimum 20 models. Literally there arehundreds of models of 8051 microcontroller available in market to choose. Some of

the major manufactures of 8051 are

Atmel

Philips

Philips

The Philipss 8051 derivatives has more number of features than in any

microcontroller. The costs of the Philips microcontrollers are higher than the Atmels

which makes us to choose Atmel more often than Philips

Dallas

Dallas has made many revolutions in the semiconductor market. Dallass 8051

derivative is the fastest one in the market. It works 3 times as fast as a 8051 can

process. But we are unable to get more in India.

Atmel

These people were the one to master the flash devices. They are the cheapest

microcontroller available in the market. Atmels even introduced a 20pin variant of


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8051 named 2051. The Atmels 8051 derivatives can be got in India less than 70

rupees. There are lots of cheap programmers available in India for Atmel. So it is

always good for students to stick with 8051 when you learn a new microcontroller.

Architecture

Architecture is must to learn because before learning new machine it is necessary to

learn the capabilities of the machine. This is some thing like before learning about the

car you cannot become a good driver. The architecture of the 8051 is given below.


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The 8051 doesnt have any special feature than other microcontroller. The only

feature is that it is easy to learn. Architecture makes us to know about the hardware

features of the microcontroller. The features of the 8051 are

4K Bytes of Flash Memory

128 x 8-Bit Internal RAM

Fully Static Operation: 1 MHz to 24 MHz 32 Programmable I/O Lines

Two 16-Bit Timer/Counters

Six Interrupt Sources (5 Vectored)

Programmable Serial Channel Low Power Idle and Power Down Modes

The 8051 has a 8-Bit CPU that means it is able to process 8 bit of data at a time. 8051

has 235 instructions. Some of the important registers and their functions are

Lets now move on to a practical example. We shall work on a simple practical

application and using the example as a base, shall explore the various features of

the 8051 microcontroller.

Consider an electric circuit as follows,


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The positive side (+ve) of the battery is connected to one side of

a switch. The other side of the switch is connected to a bulb or

LED (Light Emitting Diode). The bulb is then connected to a

resistor, and the other end of the resistor is connected to the

negative (-ve) side of the battery.

When the switch is closed or switched on the bulb glows. When

the switch is open or switched off the bulb goes off

If you are instructed to put the switch on and off every 30

seconds, how would you do it? Obviously you would keep looking

at your watch and every time the second hand crosses 30

seconds you would keep turning the switch on and off.

Imagine if you had to do this action consistently for a full day. Do

you think you would be able to do it? Now if you had to do this for

a month, a year??

No way, you would say!

The next step would be, then to make it automatic. This is where

we use the Microcontroller.

But if the action has to take place every 30 seconds, how will the

microcontroller keep track of time?

Execution time


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Look at the following instruction,

clr p1.0

This is an assembly language instruction. It means we are

instructing the microcontroller to put a value of zero in bit zeroof port one. This instruction is equivalent to telling the

microcontroller to switch on the bulb. The instruction then to

instruct the microcontroller to switch off the bulb is,

Set p1.0

This instructs the microcontroller to put a value of one in bit zero

of port one.

Dont worry about what bit zero and port one means. We shall

learn it in more detail as we proceed.

There are a set of well defined instructions, which are used while

communicating with the microcontroller. Each of these

instructions requires a standard number of cycles to execute. The

cycle could be one or more in number.

How is this time then calculated?

The speed with which a microcontroller executes instructions is

determined by what is known as the crystal speed. A crystal is a

component connected externally to the microcontroller. The

crystal has different values, and some of the used values are

6MHZ, 10MHZ, and 11.059 MHz etc.Thus a 10MHZ crystal would pulse at the rate of 10,000,000 times

per second.


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The time is calculated using the formula

No of cycles per second = Crystal frequency in HZ / 12.

For a 10MHZ crystal the number of cycles would be,

10,000,000/12=833333.33333 cycles.

This means that in one second, the microcontroller would execute 833333.33333

cycles.

Therefore for one cycle, what would be the time? Try it out.

The instruction clr p1.0 would use one cycle to execute. Similarly, the instruction

setb p1.0 also uses one cycle.


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So go ahead and calculate what would be the number of cycles required to be

executed to get a time of 30 seconds!

Getting back to our bulb example, all we would need to do is to instruct the

microcontroller to carry out some instructions equivalent to a period of 30 seconds,

like counting from zero upwards, then switch on the bulb, carry out instructions

equivalent to 30 seconds and switch off the bulb.

Just put the whole thing in a loop, and you have a never ending on-off sequence.

Let us now have a look at the features of the 8051core,

keeping the above example as a reference,

1. 8-bit CPU.( Consisting of the A and B registers)

Most of the transactions within the microcontroller are carried out

through the A register, also known as the Accumulator. In

addition all arithmetic functions are carried out generally in the

A register. There is another register known as the B register,

which is used exclusively for multiplication and division.

Thus an 8-bit notation would indicate that the maximum valuethat can be input into these registers is 11111111. Puzzled?

The value is not decimal 111, 11,111! It represents a binary

number, having an equivalent value of FF in Hexadecimal and a

value of 255 in decimal.


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We shall read in more detail on the different numbering systems

namely the Binary and Hexadecimal system in our next module.

2. 4K on-chip ROM

Once you have written out the instructions for the microcontroller,

where do you put these instructions?

Obviously you would like these instructions to be safe, and not

get deleted or changed during execution. Hence you would load it

into the ROM

The size of the program you write is bound to vary depending on

the application, and the number of lines. The 8051 microcontroller

gives you space to load up to 4K of program size into the internal

ROM.

4K, thats all? Well just wait. You would be surprised at the

amount of stuff you can load in this 4K of space.

Of course you could always extend the space by connecting to

64K of external ROM if required.

3. 128 bytes on-chip RAM

This is the space provided for executing the program in terms of

moving data, storing data etc.

4. 32 I/O lines. (Four- 8 bit ports, labeled P0, P1, P2, P3)

In our bulb example, we used the notation p1.0. This means bit

zero of port one. One bit controls one bulb.


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Thus port one would have 8 bits. There are a total of four ports

named p0, p1, p2, p3, giving a total of 32 lines. These lines can

be used both as input or output.

5. Two 16 bit timers / counters.

A microcontroller normally executes one instruction at a time.

However certain applications would require that some event has

to be tracked independent of the main program.

The manufacturers have provided a solution, by providing two

timers. These timers execute in the background independent ofthe main program. Once the required time has been reached,

(remember the time calculations described above?), they can

trigger a branch in the main program.

These timers can also be used as counters, so that they can count

the number of events, and on reaching the required count, can

cause a branch in the main program.

6. Full Duplex serial data receiver / transmitter.

The 8051 microcontroller is capable of communicating with

external devices like the PC etc. Here data is sent in the form of

bytes, at predefined speeds, also known as baud rates.

The transmission is serial, in the sense, one bit at a time

7. 5- interrupt sources with two priority levels (Two

external and three internal)

During the discussion on the timers, we had indicated that the

timers can trigger a branch in the main program. However, what


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would we do in case we would like the microcontroller to take the

branch, and then return back to the main program, without

having to constantly check whether the required time / count has

been reached?

This is where the interrupts come into play. These can be set to

either the timers, or to some external events. Whenever the

background program has reached the required criteria in terms of

time or count or an external event, the branch is taken, and on

completion of the branch, the control returns to the main

program.

Priority levels indicate which interrupt is more important, andneeds to be executed first in case two interrupts occur at the

same time.

8. On-chip clock oscillator.

This represents the oscillator circuits within the microcontroller.

Thus the hardware is reduced to just simply connecting an

external crystal, to achieve the required pulsing rate.

PIN FUNCTION OF IC 89C51.

1 Supplypin of this ic is pin no 40. Normally we apply a 5 volt regulateddc power supply to this pin. For this purpose either we use step downtransformer power supply or we use 9 volt battery with 7805 regulator.

2 Groundpin of this ic is pin no 20. Pin no 20 is normally connected to theground pin ( normally negative point of the power supply.

3 XTAL is connected to the pin no 18 and pin no 19 of this ic. The quartzcrystal oscillator connected to XTAL1 and XTAL2 PIN. These pins also needs


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two capacitors of 30 pf value. One side of each capacitor is connected tocrystal and other pis is connected to the ground point. Normally weconnect a 12 MHz or 11.0592 MHz crystal with this ic.. But we use crystalupto 20 MHz to this pins

4 RESETPIN.. Pin no 9 is the reset pin of this ic.. It is an active high pin.On applying a high pulse to this pin, the micro controller will reset andterminate all activities. This is often referred to as a power on reset. Thehigh pulse mustbe high for a minimum of 2 machine cycles before it is allowed to go low.

5. PORT0 Port 0 occupies a total of 8 pins. Pin no 32 to pin no 39. It can beused for input or output. We connect all the pins of the port 0 with the

pullup resistor (10 k ohm) externally. This is due to fact that port 0 is an

open drain mode. It is just like a open collector transistor.

6. PORT1. ALL the ports in micrcontroller is 8 bit widepin no 1 to pin no 8because it is a 8 bit controller. All the main register and sfr all is mainly 8

bit wide. Port 1 is also occupies a 8 pins. But there is no need of pull up

resistor in this port. Upon reset port 1 act as a input port. Upon reset all the

ports act as a input port

7. PORT2. port 2 also have a 8 pins. It can be used as a input or output.

There is no need of any pull up resistor to this pin.

PORT 3. Port3 occupies a totoal 8 pins from pin no 10 to pin no 17. Itcan be used as input or output. Port 3 does not require any pull up

resistor. The same as port 1 and port2. Port 3 is configured as an output

port on reset. Port 3 has the additional function of providing some

important signals such as interrupts. Port 3 also use for serial

communication.


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ALE ALE is an output pin and is active high. When connecting an 8031 to externalmemory, port 0 provides both address and data. In other words, the 8031 multiplexes

address and data through port 0 to save pins. The ALE pin is used for demultiplexing

the address and data by connecting to the ic 74ls373 chip.

PSEN. PSEN stands for program store eneable. In an 8031 based system in whichan external rom holds the program code, this pin is connected to the OE pin of the

rom.

EA. EA. In 89c51 8751 or any other family member of the ateml 89c51 series all

come with on-chip rom to store programs, in such cases the EA pin is connected tothe Vcc. For family member 8031 and 8032 is which there is no on chip rom, code is

stored in external memory and this is fetched by 8031. In that case EA pin must be

connected to GND pin to indicate that the code is stored externally.

SPECIAL FUNCTION REGISTER ( SFR) ADDRESSES.

ACC ACCUMULATOR 0E0H

B B REGISTER 0F0H

PSW PROGRAM STATUS WORD 0D0H

SP STACK POINTER 81H


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DPTR DATA POINTER 2 BYTES

DPL LOW BYTE OF DPTR 82H

DPH HIGH BYTE OF DPTR 83H

P0 PORT0 80H

P1 PORT1 90H

P2 PORT2 0A0H

P3 PORT3 0B0H

TMOD TIMER/COUNTER MODE CONTROL 89H

TCON TIMER COUNTER CONTROL 88H

TH0 TIMER 0 HIGH BYTE 8CH

TLO TIMER 0 LOW BYTE 8AH

TH1 TIMER 1 HIGH BYTE 8DH

TL1 TIMER 1 LOW BYTE 8BH


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SCON SERIAL CONTROL 98H

SBUF SERIAL DATA BUFFER 99H

PCON POWER CONTROL 87H

INSTRUCTIONS

SINGLE BIT INSTRUCTIONS.

SETB BIT SET THE BIT =1

CLR BIT CLEAR THE BIT =0

CPL BIT COMPLIMENT THE BIT 0 =1, 1=0

JB BIT,TARGET JUMP TO TARGET IF BIT =1

JNB BIT, TARGET JUMP TO TARGET IF BIT =0

JBC BIT,TARGET JUMP TO TARGET IF BIT =1 &THEN CLEAR THE BIT


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MOV INSTRUCTIONS

MOV instruction simply copy the data from one location to another location

MOV D,S

Copy the data from(S) source to D(destination)

MOV R0,A ; Copy contents of A into Register R0

MOV R1,A ; Copy contents of A into register R1

MOV A,R3; copy contents of Register R3 into Accnmulator.

DIRECT LOADING THROUGH MOV

MOV A,#23H ; Direct load the value of 23h in A

MOV R0,#12h ; direct load the value of 12h in R0

MOV R5,#0F9H ; Load the F9 value in the Register R5


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ADD INSTRUCTIONS.

ADD instructions adds the source byte to the accumulator ( A) and place the result inthe Accumulator.

MOV A, #25H

ADD A,#42H ; BY this instructions we add the value 42h in Accumulator

( 42H+ 25H)

ADDA,R3 ;By this instructions we move the data from register r3 to

accumulator and then add the contents of the register into

accumulator .

SUBROUTINE CALL FUNCTION.

ACALL,TARGET ADDRESS

By this instructions we call subroutines with a target address within 2k bytes from

the current program counter.

LCALL, TARGET ADDRESS.

ACALL is a limit for the 2 k byte program counter, but for upto 64k byte we use

LCALL instructions.. Note that LCALL is a 3 byte instructions.

ACALL is a two byte instructions.


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AJMP TARGET ADDRESS.

This is for absolute jump

AJMP stand for absolute jump. It transfers program execution to the target address

unconditionally. The target address for this instruction must be

withib 2 k byte of program memory.

LJMP is also for absoltute jump. It tranfer program execution to the target addres

unconditionally. This is a 3 byte instructions LJMP jump to any

address within 64 k byte location.

INSTRUCTIONS RELATED TO THE CARRY

JC TARGET

JUMP TO THE TARGET IF CY FLAG =1


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JNC TARGET

JUMP TO THE TARGET ADDRESS IF CY FLAG IS = 0

INSTRUCTIONS RELASTED TO JUMP WITH ACCUMULATOR

JZ TARGET

JUMP TO TARGET IF A = 0

JNZ TARGET

JUMP IF ACCUMULATOR IS NOT ZERO

This instructions jumps if registe A has a value other than zero

INSTRUCTIONS RELATED TO THE ROTATE


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RL A

ROTATE LEFT THE ACCUMULATOR

BY this instructions we rotate the bits of A left. The bits rotated

out of A are rotated back into A at the opposite end

RR A

By this instruction we rotate the contents of the accumulator from

right to left from LSB to MSB

RRC A

This is same as RR A but difference is that the bit rotated out of

register first enter in to carry and then enter into MSB

RLC A


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ROTATE A LEFT THROUGH CARRY

Same as above but but shift the data from MSB to carry and

carry to LSB

RET

This is return from subroutine. This instructions is used to return

from a subroutine previously entered by instructions LCALL and

ACALL.

RET1

THIS is used at the end of an interrupt service routine. We use

this instructions after intruupt routine,

PUSH.


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This copies the indicated byte onto the stack and increments SP

by . This instructions supports only direct addressing mode.

POP.

POP FROM STACK.

This copies the byte pointed to be SP to the location whose directaddress is indicated, and decrements SP by 1. Notice that this

instructions supports only direct addressing mode.

DPTR INSTRUCTIONS.

MOV DPTR,#16 BIT VALUE

LOAD DATA POINTER

This instructions load the 16 bit dptr register with a 16 bit

immediate value


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MOV C A,@A+DPTR

This instructions moves a byte of data located in program ROM

into register A. This allows us to put strings of data, such as look

up table elements.

MOVC A,@A+PC

This instructions moves a byte of data located in the program area to A. the address

of the desired byte of data is formed by adding the program counter ( PC) register

to the original value of the accumulator.

INC BYTE

This instructions add 1 to the register or memory location

specified by the operand.

INC A

INC Rn

INC DIRECT

DEC BYTE


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This instructions subtracts 1 from the byte operand. Note that CY

is unchanged

DEC A

DEC Rn

DEC DIRECT

ARITHMATIC INSTRUCTIONS.

ANL dest-byte, source-byte

This perform a logical AND operation

This performs a logical AND on the operands, bit by bit, storing

the result in the destination. Notice that both the source and

destination values are byte size only

`

DIV AB

This instructions divides a byte accumulator by the byte in

register B. It is assumed that both register A and B contain an

unsigned byte. After the division the quotient will be in register A

and the remainder in register B.


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TMOD ( TIMER MODE ) REGISTER

Both timer is the 89c51 share the one register TMOD. 4 LSB bit for the timer 0 and 4

MSB for the timer 1.

In each case lower 2 bits set the mode of the timer

Upper two bits set the operations.

GATE: Gating control when set. Timer/counter is enabled only while the INTX

pin is high and the TRx control pin is set. When cleared, the timer is enabled

whenever the TRx control bit is set

C/T : Timer or counter selected cleared for timer operation ( input from

internal system clock)

M1 Mode bit 1


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M0 Mode bit 0

M1 M0 MODE OPERATING MODE

0 0 0 13 BIT TIMER/MODE

0 1 1 16 BIT TIMER MODE

1 0 2 8 BIT AUTO RELOAD

1 1 3 SPLIT TIMER MODE

PSW ( PROGRAM STATUS WORD)

CY PSW.7 CARRY FLAG


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AC PSW.6 AUXILIARY CARRY

F0 PSW.5 AVAILABLE FOR THE USER FRO GENERAL PURPOSE

RS1 PSW.4 REGISTER BANK SELECTOR BIT 1

RS0 PSW.3 REGISTER BANK SELECTOR BIT 0

0V PSW.2 OVERFLOW FLAG

-- PSW.1 USER DEFINABLE BIT

P PSW.0 PARITY FLAG SET/CLEARED BY HARDWARE

PCON REGISATER ( NON BIT ADDRESSABLE)

If the SMOD = 0 ( DEFAULT ON RESET)


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TH1 = CRYSTAL FREQUENCY

256---- ____________________

384 X BAUD RATE

If the SMOD IS = 1

CRYSTAL FREQUENCY

TH1 = 256--------------------------------------

192 X BAUD RATE

There are two ways to increase the baud rate of data transfer in the 8051

1. To use a higher frequency crystal2. To change a bit in the PCON register

PCON register is an 8 bit register . Of the 8 bits, some are unused, and some are used

for the power control capability of the 8051. the bit which is used for the serial

communication is D7, the SMOD bit. When the 8051 is powered up, D7 ( SMOD BIT)OF PCON register is zero. We can set it to high by software and thereby double the

baud rate

BAUD RATE COMPARISION FOR SMOD = 0 AND SMOD =1

TH1 ( DECIMAL) HEX SMOD =0 SMOD =1

-3 FD 9600 19200


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-6 FA 4800 9600

-12 F4 2400 4800

-24 E8 1200 2400

XTAL = 11.0592 MHZ

IE ( INTERRUPT ENABLE REGISTOR)

EA IE.7 Disable all interrupts if EA = 0, no interrupts is acknowledged

If EA is 1, each interrupt source is individually enabled or disbaled

By sending or clearing its enable bit.

IE.6 NOT implemented

ET2 IE.5 enables or disables timer 2 overflag in 89c52 only

ES IE.4 Enables or disables all serial interrupt

ET1 IE.3 Enables or Disables timer 1 overflow interrupt

EX1 IE.2 Enables or disables external interrupt


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ET0 IE.1 Enables or Disbales timer 0 interrupt.

EX0 IE.0 Enables or Disables external interrupt 0

INTERRUPT PRIORITY REGISTER

If the bit is 0, the corresponding interrupt has a lower priority and if the bit is 1 the

corresponding interrupt has a higher priority

IP.7 NOT IMPLEMENTED, RESERVED FOR FUTURE USE.

IP.6 NOT IMPLEMENTED, RESERVED FOR FUTURE USE

PT2 IP.5 DEFINE THE TIMER 2 INTERRUPT PRIORITY LELVEL

PS IP.4 DEFINES THE SERIAL PORT INTERRUPT PRIORITY LEVEL


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PT1 IP.3 DEFINES THE TIMER 1 INTERRUPT PRIORITY LEVEL

PX1 IP.2 DEFINES EXTERNAL INTERRUPT 1 PRIORITY LEVEL

PT0 IP.1 DEFINES THE TIMER 0 INTERRUPT PRIORITY LEVEL

PX0 IP.0 DEFINES THE EXTERNAL INTERRUPT 0 PRIORITY LEVEL

SCON: SERIAL PORT CONTROL REGISTER , BIT ADDRESSABLE

SCON

SM0 : SCON.7 Serial Port mode specifier

SM1 : SCON.6 Serial Port mode specifier

SM2 : SCON.5

REN : SCON.4 Set/cleared by the software to Enable/disable reception

TB8 : SCON.3 The 9th bit that will be transmitted in modes 2 and 3,

Set/cleared

By software


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RB8 : SCON.2 In modes 2 &3, is the 9th data bit that was received. In mode 1,

If SM2 = 0, RB8 is the stop bit that was received. In mode 0

RB8 is not used

T1 : SCON.1 Transmit interrupt flag. Set by hardware at the end of the 8th bit

Time in mode 0, or at the beginning of the stop bit in the other

Modes. Must be cleared by software

R1 SCON.0 Receive interrupt flag. Set by hardware at the end of the 8

th

bit

Time in mode 0, or halfway through the stop bit time in the

other

Modes. Must be cleared by the software.

TCON TIMER COUNTER CONTROL REGISTER

This is a bit addressable

TF1 TCON.7 Timer 1 overflow flag. Set by hardware when the Timer/Counter 1

Overflows. Cleared by hardware as processor

TR1 TCON.6 Timer 1 run control bit. Set/cleared by software to turn Timer

Counter 1 On/off


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TF0 TCON.5 Timer 0 overflow flag. Set by hardware when the timer/counter 0

Overflows. Cleared by hardware as processor

TR0 TCON.4 Timer 0 run control bit. Set/cleared by software to turn timer

Counter 0 on/off.

IE1 TCON.3 External interrupt 1 edge flag

ITI TCON.2 Interrupt 1 type control bit

IE0 TCON.1 External interrupt 0 edge

IT0 TCON.0 Interrupt 0 type control bit.

- 8051 Instruction Set

Arithmetic Operations

Mnemonic Description Size Cycles

ADD A,Rn Add register to Accumulator (ACC). 1 1

ADD A,direct Add direct byte to ACC. 2 1

ADD A,@Ri Add indirect RAM to ACC . 1 1


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ADD A,#data Add immediate data to ACC . 2 1

ADDC A,Rn Add register to ACC with carry . 1 1

ADDC A,direct Add direct byte to ACC with carry. 2 1

ADDC A,@Ri Add indirect RAM to ACC with carry. 1 1

ADDC A,#data Add immediate data to ACC with carry. 2 1

SUBB A,Rn Subtract register from ACC with borrow. 1 1

SUBB A,direct Subtract direct byte from ACC with borrow 2 1

SUBB A,@Ri Subtract indirect RAM from ACC with borrow. 1 1

SUBB A,#data Subtract immediate data from ACC with borrow. 2 1

INC A Increment ACC. 1 1

INC Rn Increment register. 1 1

INC direct Increment direct byte. 2 1

IN


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Ivrs system diagram with mobile attachment.


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ivrs system

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