can we use large memory model variables in Evaluation Keil

It may be right bcoz i does not understand this memory model.

I know that when we use exernal memory we use xdata type.
when we are accessing not more than 256byte of external memory we use pdata.
and for inernal we use data.

But ? is How to use them in programming. Just specifying data type or something else.

My Problem is:

I want to interface device which communicate through serial communication with uC.
I checked this device using serial port analyzer it is responding but when i am giving that commands using uC it is not responding.

if i am accessing memory of that device then i have to use xdata variables so i have to use large memory model thats why i am asking can we use it.

It may be right bcoz i does not understand this memory model.

I know that when we use exernal memory we use xdata type.
when we are accessing not more than 256byte of external memory we use pdata.
and for inernal we use data.

But ? is How to use them in programming. Just specifying data type or something else.

My Problem is:

I want to interface device which communicate through serial communication with uC.
I checked this device using serial port analyzer it is responding but when i am giving that commands using uC it is not responding.

if i am accessing memory of that device then i have to use xdata variables so i have to use large memory model thats why i am asking can we use it.

Your problem is that you're trying to leap into a project before having gained the necessary understanding of the tools.

There are lots of support materials here: http://www.keil.com/support/
including the full set of manuals for the C51 toolset.

Books here: http://www.keil.com/books/8051books.asp

Training: http://www.keil.com/events/links.asp

"i have to use xdata variables so i have to use large memory model"

No, you don't have to.

Read the description of Memory Models again: http://www.keil.com/support/man/docs/c51/c51_le_memmodels.htm

"when we are accessing not more than 256byte of external memory we use pdata"

You can use PDATA - but you don't have to. Also, your hardware needs to be appropriately configured...

"for inernal we use data"

or IDATA.

Note that the terms "internal" and "external" can be misleading in modern devices with on-chip XDATA RAM...

"How to use them in programming"

Please read the manual: http://www.keil.com/support/man/docs/c51/c51_le_memtypes.htm

Thanks for giving links.

I wil study it first and understand. If i have doubt than i will ask you.

Thanks once again...