unfortunatley I couldn't follow my threads because of some distracting problems ... I thank all people who answered here.
In fact I had read posts till 20th of januray,my question had been answered then and I wanted to come back soon, but I couldn't. I'm sorry about late,
what I wanted to know was that if SFRs are located in SRAM area phisycally the answer is no , and SBUF was a good example ,also TL0,TH0,...I had forgot them! although even now I don't know about some SFRs like especially those one related to CPU like PSW,...
yes this question is not useful, but it's still a question, I asked it because I had a disucussion with a friend about data memory of 8051s then I wondered is it precise to say SFRs are part of SRAM or not. it was enough for me to ask,because I don't know the chip layout.
thank you all anyway,Koosha