串行口扩展.asm

来自「基于Proteus的51系列单片机设计与仿真」· 汇编 代码 · 共 29 行

      ORG  00H
      AJMP START
      ORG  0003H
      AJMP INT
START:MOV  SCON,#00H
      SETB IT0
      SETB EA
      SETB EX0
      MOV  SBUF,#0FEH 
      MOV  DPTR,#TABLE 
LP:   CLR  TI      
      AJMP LP
INT:  INC  DPTR
      MOV  A,#00H
      MOVC A,@A+DPTR
      CJNE A,#1BH,LP1
      AJMP LP2
LP1:  MOV  SBUF,A
      JBC  TI,LP1
      AJMP LP3
LP2:  MOV  DPTR,#TABLE
LP3:  NOP
      RETI
TABLE:DB   0FEH,0FEH,0FDH,0FBH,0F7H
      DB   0EFH,0DFH,0BFH,7FH,1BH
      RET
      END