Instruction   Cygnal C8051F226    Intel 87C51FA
Code Used      Bytes   Clocks      Bytes  Clocks
------------  ----------------    --------------
SWAP A           1        1          1      12
XCHD @R0, A      1        2          1      12
XCH A, @R0       1        2          1      12
MOV A, @R0       1        2          1      12