+#ifdef S0CON__SM0__SM1__SM20__REN0__TB80__RB80__TI0__RI0
+#undef S0CON__SM0__SM1__SM20__REN0__TB80__RB80__TI0__RI0
+// serial channel 0 buffer register SAB80517 specific(same as stock SCON)
+sfr at 0x98 S0CON ;
+sbit at 0x98 RI0 ;
+sbit at 0x99 TI0 ;
+sbit at 0x9A RB80 ;
+sbit at 0x9B TB80 ;
+sbit at 0x9C REN0 ;
+sbit at 0x9D SM20 ;
+sbit at 0x9E SM1 ;
+sbit at 0x9F SM0 ;
+
+#endif
+
+