XTHL Exchange top of the stack with HL Instruction 
The contents  of top  two location of the  stack are exchanged with the  contents of HL register pair. The contents  of register L are exchanged  with the  byte of the top of the stack  and the contents of  register H are exchanged  with the  next byte . the contents  of  the  stack  pointer register are not  changed. The instruction  format is 
           XTHL