8051 MEMORY USE IN EMBEDDED C LANGUAGE

Dear Sir, thanks I have done Acc to you now I am able to convert hex to ascii and vice versa , but now I have a problem when I am power off the then my simulation is start from starting but I am want to make it retentive when power has been off the controller remember my data and start from that point not from starting is it possible in simulation or not , if yes then how please tell me sir .

Dear sir , I face a error mostly *** WARNING L16: UNCALLED SEGMENT, IGNORED FOR OVERLAY PROCESS
SEGMENT: ?PR?CLEARLCDSCREEN?LLCD how to solve it when I am face this type of error when I am merge the different file in one how to it possible to merge different file in one file I have a two different running project but I want to merge in one project I I am check its hardware all pin are different connection there is no same pin is use for two different object .

Your data is retained in the simulation.

Write data to your eeprom.
Edit your code to just read the eprom.
Restart the simulation, you should read the saved data.

In proteus, pause (not stop) the simulation.
Click debug on the top line..
select "IC2 memory internal" to view the memory contents.

Dear sir , I face a error mostly *** WARNING L16: UNCALLED SEGMENT, IGNORED FOR OVERLAY PROCESS

Technically that is a warning not an error.
Many warnings can be ignored as long as you know what they mean.
Here you are being warned that LCD.c has code that is not being used
( CLEARLCDSCREEN() )

You could..
1: Ignore it.
2: Remove the code from LCD.c and LCD.h
3 : Use the call at least once to keep the compiler happy.

Dear Sir, thanks now I have done almost my project and now I am able to merge my both project . sir now I want to learn how to write a internal memory and which controller I have to select for this in 8051 series if there is a any other microcontroller in which have a adc and memory inbuilt and can be done a program in keil and simulate on proteus .

Dear Sir,
I want to programe for debouncing of key it is possible from anywhere from I am able to understand it is easily .

Dear sir, I want purchase a debugger for 8051 , please Sir tell me which one is best.

There is a company in china which makes 8051 microcontroller with internal EEPROM/ADC/WDT/PWM etc onchip. I am not sure if they sell in India or anywhere. Here is the link for reference.
http://www.stcmicro.com/stcmcu.html

Usually 8051 does not need a debugger maybe because it's too simple? Simulation usually does most of the job offchip. So you will hardly feel a need of a debugger.

Dear Sir, if I am not purchase debugger then how I am able to burn my hex file on controller . is it debugger and burner both are different . I have less knowledge about debugger and burner please help . tell me what I should do.

Debuggers and programmers are different things.
Which programmer you need depends on the type of 8051 you use.
The newer variants of the 8051 are easier to program than the original.

Dear Sir,
I want to purchase programmer please help me to find out the which is best for me .
and I am also want to work out other microcontroller please help me for choose in one which is the best . and also can be use for other microcontroller .