"I think now it would be more clear to you. "

Oh yes absolutley.

So you have a graphic LCD (GLCD) module with a dedicated 89c51 coded to carry out the low level routines. The firmware in 89c51 is the interface between the user and GLCD.

If the above is the case, then nobody including me, can suggest the correct function and its arguments to make the GLCD do what you want ( even that is not known as of now !) UNLESS we have information on the functions coded into the 89c51 firmware. (Whew that was a long sentence).

"Also how and where should i save the parameters which follows after the command? "

Save for what ? When the intended function is executed why do you want to save the parameter ? In case you want to store it for future recall then you have to define whether you want it volatile ( gone when powered down) or non-volatile ?

Raghu