//S0_SCON0  = SM_SCON0_REN  | SM_SCON0_SM2 | SM_SCON0_SM1 | SM_SCON0_SM0 ;
  S0_SCON0  = SM_SCON0_REN                 | SM_SCON0_SM1                ; this is how I do it (for ALL SFRs)