sfr SF_CLKSEL           = 0x97;    // SYSTEM CLOCK SELECT            

sfr S0_SCON0            = 0x98;    // UART 0 CONTROL                 
  sbit    SB0_SCON0_SM0   = 0x9f;
  sbit    SB0_SCON0_SM1   = 0x9e;
  sbit    SB0_SCON0_SM2   = 0x9d;
  sbit    SB0_SCON0_REN   = 0x9c;
  sbit    SB0_SCON0_TB8   = 0x9b;
  sbit    SB0_SCON0_RB8   = 0x9a;
  sbit    SB0_SCON0_TI    = 0x99;
  sbit    SB0_SCON0_RI    = 0x98;
  #define SM_SCON0_MODE1    0x40
  #define SM_SCON0_MODE3    0xc0
  #define SM_SCON0_SM2      0x20
  #define SM_SCON0_REN      0x10
  #define SM_SCON0_TB8      0x08
  #define SM_SCON0_RB8      0x04
  #define SM_SCON0_TI       0x02
  #define SM_SCON0_RI       0x01

sfr S1_SCON1            = 0x98;               
  sbit SB1_SCON1_SM00     = 0x9f;