No. The "volatile" keyword is a hint to the compiler that something other than the program may change the value of the variable, and the compiler should generate code that always goes out and reads the latest value of that variable rather than using a value cached in a register or something.

A good example would be if you had a memory-mapped "mailbox register." This is a register that you can read and write but also some other external hardware may read and write it independent of the micro.

Since the 8052 doesn't have any real MMU hardware (it doesn't have a cache), then I think that this keyword doesn't actually do all that much for you, especially regarding automatic variables. However, as Andy Neil points out, declaring a variable to be volatile forces the compiler to assume that something else (whatever that may be) may use it and so it (and code that manipulates it) won't be optimized away.

--a